After the good people at the Concordia University Computer Store were able to sell me a copy of Mac OS X Snow Leopard shortly after launch day, I enthusiastically installed it on my Rev A Macbook Air. The first gen Air, while gloriously thin, has a few shortcomings in the speed category. Well, snapily ever after, my Air did indeed benefit from Snow Leopard, and now shuts down in just four (4!) seconds.
As for my main workhorse, my iMac at home, I was quite a bit more hesitant to install the OS. I waited until MediaLink and CoverSutra, two programs I use a lot, were updated with new betas to support 10.6.