Twisted Pixel, best known for Splosion Man, has split off from Microsoft, and is once again an independent studio, according to a report from IGN. This isn't the first time Microsoft has allowed a developer to go off on their own; it happened to Bungie back in 2007. Given Destiny's success, perhaps they regret that decision now.
There have been discouraging signs from Twisted Pixel, though, involving anything that doesn't begin with the word Splosion. Comic Jumper had promise, but ended up being pretty lame. Read the report from IGN here.