The thing that finally made me install Chromium? The refusal of Google+ to work with Firefox 3.5 (from Debian/testing). Well played Google. Well played.
Update: Please note I didn't say "switch to Chromium", it was just installing it at all. I've also pulled in FF 5 from experimental which seems to be working nicely - I hope that it can make its way into unstable and thus to testing soon.