problems, results, top 5 on the left, official blog, my screencast). For the second year in a row, those provide an opportunity for people who don't qualify for the onsite to get together, but this year one could also qualify for a special Wildcard round from the regional event, in order to compete for 2 extra spots in the onsite. That resulted in much more serious competition, but the social element was still there, and I've enjoyed meeting many of my old and new friends in St Petersburg - thanks a lot to TopCoder for organizing the regionals!
On the following Sunday, AtCoder Grand Contest 004 took place (problems, results, top 5 on the left, analysis). semiexp has won his second Grand Contest, and reclaimed the top spot in the rankings - congratulations!
Thanks for reading this super short summary, and check back soon for this week's contests! Please remember that I'm happy to answer your questions in comments to this or any other summary.