Catch is a good service. Much closer to Evernote than the old Springpad, but definitely taking steps to differentiate itself. It definitely may be an alternative for note takers who don’t like the Springpad changes.
Catch has a nice interface and some decent collaboration features — I don’t believe it does task management, however. A closer alternative for those who want task management in a pretty and free app would be Wunderlist or Wunderkit. They are a bit light when it comes to information capture, however, so you may need to supplement. Same goes with Producteev, which is a personal favourite of mine for task management.
Any other useful ideas as to alternatives for Springpad users that can’t use the changes?