My blog have been looking empty the last days for everyone except me. Kind of weird? Yes. I upgraded to WordPress 2.7 when it was in RC1 after a test on my private LAMP-server. Everything looked as it was supposed to. I got noticed about this yesterday, wrote a blog post, twittered about it and got it confirmed that my blog was just a wallpaper.
I first changed to a theme I had read was 2.7 compatible, no help in that. I had earlier trouble with the widgets Google FriendConnect and Wall. Disabled several others as well and that made my blog visible again.
Some widgets can make your whole blog go blank, so some tests in advance before you upgrade can help you avoid downtime.
One important thing to do is to test it from a browser that does not have your credentials stored. You must be logged out. The reason for me not discovering it was that I only did testing logged in as administrator. I never saw the problem.
Happy upgrading 
Wow, that’s bad! Was it one specific plugin that did it, or was it a combination of plugins? Which one(s)?
Cool that you’re linking to your identi.ca account, btw!
Hi Børge, I did not test all combinations, I just removed the most advanced ones so I could get back online asap. The Google Friendconnect was problematic and I also suspect the Last.fm widget showing my favourite artists to be one of my showstoppers.
Regarding identi.ca so will I use it more when my favourite twitter app Tweetdeck supports it. I like it for showing all tweets regarding my favourite gadgets and sw.
Alright. I totally understand that you where more worried about getting your blog back up ASAP than to find out exactly what was the problem. I’m glad you where able to fix it fairly easily.
You should go here and vote for identi.ca support in TweetDeck. No registration required.