512MB Video
1GB system with -512MB reserved (yay web browser on the tablet while gaming)
that would be a nice leap over current gen
Possibly they could go for unified 1GB (if they want to be stingy) and still end up with more usable RAM with 512MB reserved
Or 256MB video + 1GB system
with
360 = 512MB -32MB reserved
or
PS3 256MB Video + 256MB system -50MB reserved
@TheVoxelman on twitter