>>MOTU has posted new drives, both MIDI and Audio, by the way, for Snow Leopard compatibility.<<
The firewire driver came out about two months ago, but the midi driver is new. MOTU's site notes that Ethno is not working, and I can confirm this. Trying to load it or even do the AU validation crashes Logic.
Here's what's not working for me with Logic 9 and Snow Leopard, besides Ethno:
Predator, Circle and Symptohm work in Logic 9 (for some reason, Predator comes up with the "reverse" side onscreen instead of the control side, but clicking on it returns the plug to working status), but they crash Kore 2.1, whereas they worked in Kore 2.1 before.
Independence Pro 2.5.1 works, but the font used when I'm loading sounds looks jagged.
Kore 2.1 works in L9 with 10.6 with everything else I have tested, including all the NI plugs, all the Lin Plug stuff, the other Rob Papen plugs, the Arturia stuff, all the AAS stuff, the Image Line AU plugs, and the new FXpansion plugs. Kontakt 3.5 is fine.
Waves API, JJP, GTR3, and other Waves bundles seem to work fine. All Sonalksis and Sonnox plugs seem to work fine. All of the IK plugs I've tried so far work including the instruments and the effects.
I'll keep reporting as I go, but so far, so good. I've noticed a few glitches in overall operation; for example, selecting several Aux channels in the Mixer to include in the Arrange window so I can automate them caused the mouse pointer to go slow and jumpy. A restart fixed this.
I've had my wireless keyboard get "lost" a couple of times, but simply pressing the ON button again allows the Mac to find it very quickly.
It's feeling a bit like being a beta tester with this, but it's kind of fun. And clearly, I can work without too much problem, so...I'm actually glad I upgraded just for that.