I doubt it for two reasons:
1) There is no physical reason the current iPhones can't do that (beyond being deliberately crippled by Apple) - it's not a hardware limitation but a very limited bluetooth stack implementation. Apple made a conscious decision to not allow it so I doubt they'd change their minds: It's certainly not available in the 3.0 software for the iPhones or iPod touch (2nd Gen)
2) If it were available then it would have been heavily advertised as a new feature. It hasn't, so it won't be