Yes, you're right, and it hasn't been added in to the Mac version either.
So, where does that leave Airprint for shared printers? It's in iOS4.2, but it's not in OS X or Windows. Hmmm...
At the moment, if we want to use Airprint over shared printers, then there are only 2 options
1) do the '3 files' workaround in OS X
2) use the 10.1 beta Windows iTunes.
I don't understand this at all!