"Sega has made the decision not to attend Gamescom this year. Unfortunately the release timing of our 2012 triple-A titles and new projects don't work with the mid-August scheduling of the show. The decision will not mean that Sega will never attend Gamescom in the future, this was simply a commercial decision made for 2012." - SEGA statement
Both SEGA and Nintendo have backed out of this year's Gamescom, making for two rather high-profile no-shows. I wonder if this is the last of the companies to back out this year.