Delivery was indeed imminent, as the new Pinnacle Station downloadable content for Mass Effect makes its way onto Xbox Live.
The Pinnacle Station DLC has had an interesting sort of announcement history, at one point teased as the announcement of an announcement that would never actually come. Well announcement be damned, the DLC is now live and available for purchase for 400 Microsoft points. Taking place on a top-secret Alliance space station, it features a number of arena-style battle exercises that should tack on a good 2-3 hours to the game.
Considering how long I played Mass Effect, that's a drop in the bucket, but it's certainly better than nothing at all.