It's always done AAC, jasonkchapman, it's not an addition, just not much commented on.
I'm a bit surprised they didn't at least jump to USB 2.0.
There may be some other, internal, changes that aren't apparent from the specs that might make it a bigger deal, we need more information to evaluate that, though.
Ah, yes, I meant to mention before: Can't tell if there's Vizplex on the rascal or not, but I'd be moderately astounded if there weren't.