The Web Services and Context Initiative has a number of outstanding patches that are in urgent need of review, as they are turning into blockers for other work, have been sitting for a while, or both. :-) If you have any spare time, thoughtful review of the following would be greatly appreciated:
http://drupal.org/node/1606794 - The new routing system. Architecture is in place, some functionality is in place, but not all of it. Feedback now or forever hold your peace. :-)
http://drupal.org/node/335411 - We have this great new Symfony session system in core, complete with improved flash messages that were improved specifically for us. We should be using it. There's a patch waiting review. It will need some refactoring with recent developments but reviews now are still valuable.
http://drupal.org/node/1728666 - Although modules can now expose "bundles" (Symfony equivalent of modules), they're not able to override core services as much as we want them to. This attempts to do so. (It's also a good small introduction to Symfony if anyone is looking for that...)