Larry “Major Nelson” Hyrb has let the cat out of the digital bag when it comes to upcoming content for Xbox Live over the next couple of weeks.  You can expect plenty of great new games, as well as some highly anticipated downloadable content and other goodies.

In the Xbox Live Arcade games department, Jeremy McGrath Offroad Racing from D3 Publisher will drop this Wednesday for 800 Microsoft points, and, on Friday, you’ll be able to check out Square Enix’s Mini Ninjas Adventures for the same price.  Next week will bring all-American gaming fun to the service, with the release of the independent hit Spelunky and the brawlfest Bellator MMA Onslaught, both arriving on July 4 for 1200 Microsoft points each.

As for add-ons, today brings the long-awaited Skyrim Dawnguard for 1600 Microsoft points, as well as the free Mass Effect 3: Extended Cut add-on and the Close Quarters maps for Battlefield 3, priced at 1200 Microsoft points.  Next week, you’ll be able to snag a Forza Motorsport 4 July Car Pack for 560 Microsoft points.

As far as new Games on Demand, this week brings Grease Dance and the race-heavy Cars Mater National to the service, with Cabela’s North American Adventure slated to arrive next week.

Finally, if you want to dress up your avatar in cool outfits, you can buy a Ninja, vampire, werewolf or Spongebob Squarepants get-up starting July 3, as well as offerings from the Adidas Summer Sports collection, as well as Surf and Skate.

There you have it.  Plenty to download over the next two weeks.  Have at it!