Please take these with a grain of salt until we get the codex in hand.
rumors via Yakface
Overlords
Necron Overlord: Generic DIY Necron Overlord (guy who rules a Tomb World) with plenty of options. Can ride on a Catacomb Command Barge and/or take a Royal Court.
Generic Overlords start with a Staff of Light (regular CC weapon that also has a 12" S5, AP3, Assault 3 shooting attack). They can exchange (and in some cases pay more points for):
• Warscythe
• Gauntlet of Fire
• Hyperhase Sword
• Voidblade
I think I've discussed all those weapon options before in other unit descriptions, so I won't bother going over them.
They also have the option to take any of the following Wargear:
• Phylactery
• Mindshackle Scarabs
• Sempiternal Weave
• Tesseract Labyrinth (one use only. choose a character or monstrous creature in base contact and instead of making CC attacks the victim must roll under its remaining wounds on a D6 or be removed as a casualty with no saves allowed).
• Tachyon Arrow
• Resurrection Orb
• Phase Shifter
• Destroyer Lord: Basically the same as an Overlord but with Preferred Enemy against everything (Destroyers now hate everybody). CANNOT take a Royal Court.
Destroyer Lords
Destroyer Lords come stock with the Warscythe and have the same weapon options as the Overlord (except they can't get the Staff of Light).
The only wargear choices Destroyer Lords have are:
• Sempiternal Weave
• Mindshackle Sacarbs
• Tachyon Arrow
• Resurrection Orb
Royal Court
• Royal Court: 0-5 regular Necron Lords (lieutenants to the Overlords) as well as 0-5 Crypteks (can take 0-5 of either or both, for a minimum of 1 model or a maximum of 10). Crypteks are masters of Necron technology, whose abilities sometimes appear like sorcery to other races, but they do not have any psychic powers...all their abilities do not require a psychic test or anything like that (nor are they ever referred to as psychic powers in any way). Any member of the Court (Lord or Cryptek) can be split off at the start of the game to lead a unit of Warriors, Immortals, Lychguard or Deathmarks (but only one per unit).
The Royal Court does not take up a HQ slot but may only be taken one per each Overlord (including the named ones) you take in the army.
Crypteks and Basic Lords
Crypteks vs. (basic) Lords in the 'Royal Court': both have more like squad leader stats then character stats (1 wound each for example) with both of their base points are in the exact same range as an IG Commissar, for example. However, all of the upgrades for these guys clock in the 5 to 45 point range (each option) with probably a 15 point median for their gear, so you can imagine that these guys will very quickly eat up your points if you give them many (or any) upgrades.
These (lesser) Lords come standard with Staff of Light but can upgrade it to (for a number points):
• Warscythe
• Gauntlet of Fire
• Hyperphase Sword
• Voidblade
And they can take any of the following gear (for a number of points):
• Sempiternal Weave
• Mindshackle Scarabs
• Tesseract Labyrinth
• Resurrection Orb
• Phase Shifter
Of all those weapons and upgrades only the Rez Orb benefits the unit. The rest of the upgrades just give the Lord extra benefits in combat or armor save.
So really, if you're looking to make the Lord improve a unit by leading it, besides adding some CC punch to the unit your only real choice is the Rez Orb and the Rez Orb is on the high end of the points scale for their wargear so it isn't exactly a steal to get a Rez Orb into a unit (which for those who aren't keeping up boosts that unit's, and only that unit's, Reanimation Protocols to a 4+).
Crypteks can be taken plain jane if you wanted (with only a Staff of Light), but if you want to upgrade them at all, then you have to select a 'discipline' that they follow. There are five disciplines to pick from and each one costs some amount of points to take, with the only benefit being that you get an upgraded weapon instead of the staff of light that fits into that discipline's role (all but one of these upgraded weapons are improved shooting attacks).
The 5 Disciplines are: Harbinger of Destruction (described as 'plasmancers', weapon is Eldritch Lance, wargear choices are Gaze of Flame & Solar Pulse), Harbinger of Eternity (able to read the future, weapon is Aeonstave, weargear choices are Chronometron & Timesplinter Cloak), Harbinger of Transmogrification (described as 'geomancers', weapon is Tremorstave, options are Seismic Crucicble & Harp of Dissonance), Harbringer of the Storm (described as 'ethermancers', weapon is Voltaic Staff, options are Ether Crystal & Lightning Field) & Harbringer of Despair (described as 'psychomancers', weapon is Abyssal Staff, options are Nightmare Shroud & Veil of Darkness).
Now, once you've chosen a discipline to upgrade to, you're allowed to give the Cryptek one (or both) of the listed wargear options. HOWEVER, the rules state that 'each of the wargear options can only be chosen once in each Royal Court'. So the only way you're going to get more than one Veil of Darkness (for example) is to take a second Royal Court and even then you're only getting a second one. So you will be able to spam these items.
Harbinger of Destruction
• Weapon: Eldritch Lance (36", S8, AP2, Assault 1)
• Potential Wargear: Gaze of Flame (Assault/Defensive Grenades for the unit) & Solar Pulse (covered in Imotekh's rules above).
Harbinger of Eternity
• Weapon: Aeonstave (a regular CC weapon except: Any model that suffers an unsaved wound from it loses 'fleet' if it has it and reduces its WS, BS, I, & A to '1' for the rest of the game).
• Potential Wargear: Chronometron (The bearer, or his unit, can re-roll a single D6 each phase) & Timesplinter Cloak (3++ save).
Harbinger of Transmogrification
• Weapon: Termorstave (36", S4, AP-, Assault 1, Blast weapon that causes an enemy unit hit by it to count as moving in difficult terrain in their next movement phase).
• Potential Wargear: Seismic Crumble (A single enemy unit picked at the start of the enemy's assault phase has its assault move reduced by D3" if attempting to assault the Cryptek's unit) & Harp of Dissonance (Unlimited Range, S6, AP-, Assault 1, Entropic).
Harbinger of the Storm
• Weapon: Voltaic Staff (12", S5, AP-, Assault 4 weapon that hits vehicles like Haywire Grenades: roll a D6 and 2-5 = glancing hit, 6 = ).
• Potential Wargear: Lightning Field (Enemy units assaulting the Cryptek's unit immediately suffer D6, S8, AP5 hits) & Ether Crystal (Any units arriving by Deep Strike within 6" of the Cryptek D6, S8, AP5 hits. If there is more than one Ether Crystal within range then you just increase the number by 1...so a total of D6+1 hits).
Harbinger of Despair
• Weapon: Abyssal Staff (Template, S8, AP1, Assault 1, roll against target's Ld instead of Toughness, does not affect vehicles).
• Potential Wargear: Nightmare Shroud (Each Necron shooting phase, pick an enemy unit within 18" and force them to take a morale test) & Veil of Darkness (Same as before but cannot be used to pull the unit out of combat).
So in general I think the basic Lord is what you take if you're trying to give the Royal Court some CC punch (or give a unit some CC punch)...besides the obvious Rez Orb choice, of course! Instead, if you're wanting to upgrade your unit to have some unique abilities and a specialty shooting weapon in it, then the Cryptek is the way to go.