If you plan on doing some Mass Effect 3 multiplayer, now is the best weekend to do it. This weekend is the N7 Bounty Weekend which provides a 25% XP boost. If you play the horde-like multilayer Between 5 PM PST Friday, March 23 and 5 AM PST Monday, March 26, you'll benefit from the XP boost.
The multiplayer is actually a lot of fun. One night I saw myself doing match after match for as close as four hours. Guess I'll be doing more of that this weekend.