For the record as 3lions said Edge has a fractured jaw which is why he hasn't been working, but will be cleared and ready to go at Mania. This is currently the only injury Edge is suffering from. the original injury report in the 1st post is false.
WWE can't have two mania streaks going at the same time it becomes stale, so either Taker or Edge is losing at Mania
source: Wrestling Observer Newsletter
Edge hasn't wrestled much as of late due to an injury. He has a banged up jaw. He may not be 100% at WrestleMania, but the expectation is that he'll go full-time again starting with that event. His injury also explains why he hasn't appeared on recent house shows.