STEVEN GOODHEART Huzzah -- well ahead of the October release date mentioned at the MS site, they released a great Snow Leopard compatible update that works like a charm. My MS Natural 4000 keyboard once again has full functionality (but many thanks for USB Overdrive for standing in the gap until then and giving me 90% compatibility). My MS cordless laser mouse is also fully functional, although USB Overdrive handled every feature of the mouse.
I love that the Pref Pane is 64-bit and so doesn't have to reload itself like a lot of my other Preference Panes do. Couldn't be happier, and as another reviewer has said, I give MS props when it does something right. As for their keyboards, I think they are the best on the market, and believe me, as someone who makes a living at a keyboard, I've tried dozens of different ones over the year and for me none have been as comfortable as MS's ergonomic series (4000, 6000, etc.) When I use a regular keyboard, without the MS's ergonomic's splayed layout, I feel like my arms and elbow are scrunched together (because they are), and my typing speed goes way, way down, not to mention getting aches and pains. Of course, there are other good ergonomic keyboards -- Logitec makes one-- but I much preferred the keyboard feel and functionality of the MS keyboard after trying both.
Anyway, this review is about the software update -- it's five star, and if you spend hours typing, you might want to look into Microsoft's ergonomic keyboards; they are superb.
(Version 7.01)