This article is obsolete. It will only work from now until the date when openSUSE 12.1 is released. The new article, which works from now (9 Novenber 2011) onwards is located here: HowTo Upgrade openSUSE 12.x to Tumbleweed. Despite the title, it works for 11.4 just fine.

If you have a working version of Tumbleweed based on openSUSE 11.4, this article might interest you: HowTo Prepare 11.4-based Tumbleweed for openSUSE 12.1

Warning: Tumbleweed ...