I know New Mombassa has had a major redesign, but are there any areas from the halo 2 versions (E3 2004 and Shipped Game) that you'd like to play through?
Personally, some of the E3 version would be great and the part with the two wraiths before the scarab encounter would be cool. It'd be even better if the destroyed scarab was still there in the ODST campaign. That'd be real attention to detail from Bungie.