I think the main reason I liked Vanu was they were the only MAXes that could jump over the walls. I hope they retain that ability over the others 
The hovercraft were nice too when you actually had those epic fights between bases instead of those spamfests that occured inside bases. Thats really the one thing I hope they get right in the new game, everything else could be almost exactly the same as before for all I care.
Even tho Vanu MAXes will have a different ability, the TR's "mobile infantry" sport a nice jump pack that promises a quick hop with little floating nonsense.
Ofc the NC and Vanu have mobile infantry with a similar ability. From what I recall, the NC's will offer a gigantic floaty leap and the VS will be able to hover around a bit. Don't quote me on that, though.