Here are some leaked images for the rules for both pre-orders this weekend out of today's White Dwarf. They give you a good look at both of these new units and how they will play on the tabletop. For the most part we have seen these in either German, or translated, so here they are in English if you have not seen them yet.
Here is a quick link to the leaked images
Here is an overview of their rules
Sicarian Infiltrators 185pts
WS BS4 S4 T3 W2 I4 A2 Ld8 Sv4+
Stubcarbine and powersword
Nerostatic Aura -reduces BS WS Initiative and Ldrship of enemy models within 6"
can include up to 5 more at 35pts each
can replace stubcarbines and power swords with fletchette blasters and taser goads for free
the princeps may take an infoslave skull
Same stat line
may take 5 more for 30pts each
can replace wargear with two transonic blades
a pinceps with two transonic blades can also take a chordclaw. he can also tke a prehensile dataspike