10.4.9
go ahead and do it, but please check what software you have, some 3rd party software , particulary audio unit plugins that may work on garageband, and Logic in particular, may not work correctly or not at all , and need updating. Other than that, I know of no issues.
FIY:
Apple updates, are not nearly as bad as Vista , my friend has a brand new HP 2200 notebook (with a Turion 64 cpu), that came preinstalled with Windows Vista home edition, and while it looks refreshing, compared to XP, it is soo much worse in stability , it just crashes for no reason, and sometimes takes 3 to 4 attempts to start up, failing with different reasons etc. Some other person I know that also has a HP notebook with Vista, looses his network settings everytime he starts up, so always leaves it in sleep mode to prevent that.
These are the kind of bugs that Apple will not afford itself, not even at the release of Leopard. No doubt there will be a few smaller problems, but nothing that renders your computer near useless, and downright frustrating to work with. (Both these friends are in the process of downgrading to XP, I told them to buy a Mac .....)