Well, I finished the 150+ meg download and install to the iPhone. Looks like I lost all my third-party native apps, but nothing actually got broken. The iTunes store works very well over WiFi – the search is almost instant, and the preview of the song starts very quickly as well.
I seem to have lost a few of my settings, like 24h time, but overall, the upgrade went just fine. Now, I just have to wait for Nullriver and friends to come up with a new version of the Installer.app install, iBrickr, and other nice toys to work with this new firmware update. Or, pass me a winning lottery ticket so I can quit work and lend a hand!