Not a show stopper. But I don't know the first thing about Python and didn't want to have to learn how to install (and config it if something went wrong).
On Windows, installing Python involves double clicking on the installer, pressing the "Next" button until it turns into "Finish" and then pressing that. No configuration should be required.
But point taken. It would be cool if Python were bundled with the Windows SDK.
I think Google supporting PHP in app engine is newsworthy in that it gives a big nod of support to a community that has been reinvigorated of late. The app engine hoops will probably keep the wordpress crowd away but give people running serious apps another hosting option. I'm not on the PHP train but I know a lot of folks that are and this seems like a boon for their crowd.
