The Scourge Invasion isn't particularly crafting related, but it is faction related so I thought I'd bring it up. Some of you may remember this event from a couple of years ago, but now it's back and it's been tweaked for the Lich King. The undead mobs and their drop goodies are now level 70, so if you have any alts who could use a upgrade this may be an easy way to do it.
For completionists, this is also a chance to work on your Argent Dawn rep if you feel so inclined. There are two achievements associated with AD and some possible cross-over value in WotLK. I haven't actually spotted anything related to AD in the beta, but that doesn't mean it won't happen. If you're one of those folks who likes to be on the safe side, it can't hurt to jump in on the fun and get some extra AD rep as well.
There are recipes associated with the Argent Dawn faction, although nothing above level 60 at this time. Personally I wouldn't be surprised if this faction gets updated at some point in WotLK. If you plan to participate anyway, make sure you equip your Argent Dawn Commission to collect scourgestones for extra rep.