Today they've got quite a bit of coverage online, and a plug to buy Snow Leopard through their Amazon affiliate link. Note their very useful compatibility lists (see also)! ...
I'm a skeptic, but I am getting the impression that 10.6.0 is far less buggy than 10.5.0. Note 10.5.1 is expected within the next 2-3 weeks.
Update: Looks like there are serious issues with FileMaker 10:
... FileMaker Pro 10 has issues such as .fp7 not opening (not such a big deal, open FMP10 first then open the file) but export to Excel doesn't work, and that's more significant as there is no work-around. No update available yet...I'm still on FileMaker 8, so it wouldn't be surprising if the update breaks that release. Replacing FM would make 10.6 very expensive for me. On the other hand another reader reported FM 5 was working!