Good news: It's in the app store, works with Lion (10.7), lots of new features and support for GNTP
Bad news: It's in the app store (for $1.99), you MUST have Lion to use it.
I'm not sure how temporary this is. If I were releasing a desktop app that used Growl, I'd be rolling my own replacement right now ;(
It's easy enough functionality, when you're only supporting one app, and I don't want functionality for my-users to depend on a paid app they may not have.
Adium was a big driver for Growl adoption. It'll be interesting to see what they do.
I absolutely agree. They have a notification system infrastructure on iOS, and leaving that to a third party on OSX seems sloppy.
I imagine they would argue that per-app notifications (badge icons, etc) don't require system-level integration, but as I think they've learned from iOS5 apps, there's more you can do, and it's really nice to have this in one central place.
Maybe Lynx, or whatever they call 10.7, will have them.