Dudes- patience, 3rd party airplay just isn't ready yet- but its coming. I'm sure Apple wanted to have it ready but couldn't get it right before the promised 4.2 Nov release. This has happened over and over with iOS features- we bitch and moan that a feature is not available, a jailbreak comes out and the dev community makes some magic happen but its a hack and not for the masses ( as it has for airplay), then a few months later Apple releases the official feature that works perfectly- and you forget about all the agonizing weeks you couldn't live without the feature, are happy for a brief moment, then move on to the next missing feature.
Its not that Apple wanted to limit airplay- the code just isn't ready- and they are not going to release anything half-a$$ed.
I'm starting to think Apple is getting over-stretched and cant juggle so many lines as well as we all would hope.