This is where we're at too, the timeouts just don't work -- same behavior -- running out of his room etc. What I've found is to give him a little of something he wants (5 minutes of legos) before I need something (getting dressed for school). That way I'm not trying to force something "right away" and thus avoiding a confrontation in the first place. Once the power struggle begins, there's not really a smooth way out of it.