I'll add a bit here. I broke my site into subdomains based on about 6 major subjects (301'd all content to new locations). I figured this could help me separating good from bad content and let the bad content (in google's eyes) sink itself and the good content would rise.
I also saw an almost immediate recovery to pre-panda traffic for about 1-2 weeks for all subdomains. Then the content that I thought was super-excellent dropped like a rock (down 70-80%) and the content I thought could be considered marginal dropped by only 10-30%. Overall traffic evens out around 60-70% down - my pre-subdomain levels.
Long/Short - Subdomain to re-pandalization was about 2 weeks (as everyone else states). Doubt a new domain would be any different - but would be interesting to see.