I tend to fall into the "most deities would squash a party of high-level PCs like bugs" camp, though I've had parties deal directly with (or against) greatly-weakened deities e.g. Tharizdun in his Forgotten Temple.
I never understood why the deities were statted out at all, as giving them stats implies they are...somehow...defeatable. When I started DMing, one of the first changes I made was to decide the divine stat blocks presented in Deities and Demigods simply did not exist, period. The way I see it, even a deity cannot kill another deity directly; deities get their power from their followers, so to weaken the deity you need to take out all the followers...and for quasi-universal deities such as Moradin and Corellon, with followers on just about every world ever played, that's gonna take a while.
Lanefan