Lots of new models are mentioned in this rumor bit for the Imperial Guard. A new massive tank, fighter and much more are included. This list seems rather logical and a new dogfighter and big tank would also be very welcome, not to mention a storm trooper/ veteran plastic kit.
Please remember that these are rumors
via Big Red on BoLS
New plastic tank based heavily on the Heresy-era Malcador. Large kit outsizes the Land Raider (way smaller than a Baneblade) Multiple variants in the kit.
Updated Basilisk returns. Gun assembly is more rearward with armored skirts replacing the delicate railing. An overall more up-armored appearance.
A NEW dogfighter flyer arrives, that is NOT an existing known model.
New Plastic Stormtrooper/Veteran kit will build a minimum sized unit. Kit includes a TON of optional bits to individualize your squad as well as bits to dress up existing Cadian ranges.