MG Zaku Mine Layer - It looks like the changes made for this new MG Zaku are just the backpack, the legs (changed from Type J to Type F for space use), and the head. Interested?
Image from ModelGraphix March issue magazine scan.
SHCM-Pro Char's Zaku II - The overall design is based on its MG Ver. 2.0 release, evidenced clearly from the tri-boosters on the back of his legs. But so far there's no sign of any hatch-opening ability, and the list of weapons included seems really short ^^;
Image from Hobby Japan March issue magazine scan.
HCM-Pro Tieren Ground/Artillery Type - Amazingly, the conversion between the two modes seems really simple XD
Image from Hobby Japan March issue magazine scan.
HGUC Nu Gundam - Being able to mount the shield on the side of the forearm sure will increase the pose-ability of this Gundam ^^
Image from ModelGraphix March issue magazine scan.
Speed Grade God & Zeta Gundam - God Gundam's pose-ability seems really good being a SG model :)
Image from Hobby Japan March issue magazine scan.
GFF Zeong/Perfect Zeong - Sure is huge, but what about its articulation?
Image from Hobby Japan March issue magazine scan.
Also, a few new U.C.H.G. models are under development, not sure if all of them will get released though.
Zeon's amphibious Tank from The 08th MS Team.
Unknown Zeon Jeep for me ^^;
EFSF's Type 61 Tank - being an 'omnipresent' tank as seen in the original Gundam anime, I believe we'll seeing this UCHG soon.
Images from Hobby Japan March issue magazine scan.