Frankly, given the atrocity that was Command & Conquer 4, they had better come up with something pretty goddamn amazing to get my interest back.
Ever since EA took over, the franchise has gone downhill. Command & Conquer 3 was the last truly good one, Red Alert 3 was already pretty piss-poor, and Command & Conquer 4 is the biggest embarassment in the entire franchise history.
Hell, C&C4 wasn't even supposed to be released as C&C4. According to an old programmer, the game was supposed to be a game for online only for the Asian market, to test the waters as it were. In came EA's big business officials, who decided "Hrmm, what makes business sense... Add a single player and smack a big shiny 4 on it, that'll sell!"
In my opinion, C&C4 should be erased from the canon and franchise history, and the next one should be the ACTUAL C&C4: As it should have been.
EDIT: Source of claims:
http://www.gamereplays.org/community/Candid_interview_with_former_CandC_Developer_Greg_Black-t633194.html