We’ll have Snow Leopard tomorrow for sure, but if you’re still not sure of purchasing the upgrade due to the programs you use then you will want to check out the new compatibility list.  Someone along with a community has posted a wiki page showing the compatibility issues with programs and how they work or don’t work so well with SNow Leopard.  For the most part it looks like compatibility will be a non issue unless you have major workflow going thru the few non-working programs.  You can see the list [Here]