I've also been looking at the Panasonic Lumix FZ8. Similar features to the Oly 550UZ, but reportedly the RAW mode delay is only on the order of 3 vs. 6-8 seconds. Much better reviewed overall at dpreview.com
The downside is I can't find a single underwater housing for it, so far....(sigh)
Frankly I don't care so much about the UZ capability, underwater, although it would be nice to have for land use. I just want a good either compact or DSLR in the 6+ MP range, with white balance override (would be willing to skip that if it had RAW, perhaps, but would seriously prefer both), RAW that doesn't take ages, Aperture-priority auto capabilities, and a reasonably speedy AF with some zone choices, that has a housing to go with it.
Are we asking that much? Focusing on the wrong stuff? I freely admit my personal comfort with task loading means I don't really want to have to do full manual mode shooting or WB adjustments too much on the fly, hence the preference for Aperture priority and a RAW output for post-processing. Yet even the 'for dummies' underwater point-n-clicks skip RAW it seems....