I am a strong Appleite and only have been for less than 2 years. Mainly through being a K-12 Music educator. I have a recording studio in the room, three portable music stations (MBP) and 3 iPads in the dept. that enable the kids to learn at an excellerated rate. We now also use the iPad in conjunction with a 44" flatscreen with the Apple TV that is patched into an audio system in the room. ITS AWESOME. Though my personal MBP is out-dated for the airplay and I too am discouraged, the other MBP in the dept will be able to utilize this app. And with the great forum, found the ability to still do this with AirParrot.
The mistake Apple made was promote the ML system requirements as one package, when in fact, I feel it would have been better to do so per utility within the package. There was literature out there stating requirements, but you would have only found it if you were looking. I do agree that watching the keynote presentation made followers feel that any MBP 2007+ would work with all the features, but as a paranoid tech user, I wanted to make sure.
Again, I too, am not happy. But as an educator, it needs to be looked at in perspective. 2 years ago I would bash Apple on price, practices, etc. Now that we've actually had them in hand, I'll never go back to PC, nor promote it. Even though I can't do what I want to do with my 2010 MBP, I can still do a great deal more on my 2010 computer than most 2011/12 PC's can do.
I can only hope that Apple finds these posts, (and the reviews in the APP store are reflecting these) and works hard to correct if possible.
Just some words from a dissapointed, yet thankful public educator.
JB