It's unlikely. As mentioned by someone else, the A5 processor has RAM built into the chip itself. Apple would have to have an entirely seperate manufacturing process to make chips with 1gb of RAM in.
I can't see any reason at all why it would make sense for them to do that when essentially most users who don't visit macrumors wouldn't know or care whether it had 512mb or 1gb of RAM.
balls. Really wish they'd just put the bloody A6 in here and be done with it....
Ahh, 512Mb it is then.
Oh well we shall see how well it runs in real life soon enough.