I recently stumbled over the Ubuntu for Tablets video, where Mark Shuttleworth presents how Ubuntu is going to look on tablets.
However, he said one thing that struck me at: http://www.youtube.com/watch?v=h384z7Ph0gU&t=5m15s. He said that Ubuntu could run "all Windows apps".
How does this work? Was he talking about Wine (which definitely can't run every Windows program) or did he mean something else?