Nothing for the DS or 3DS this week either. I wouldn't have bothered posting this until the Virtual Console/WiiWare games come out, except for...
Rock Band 3 DLC (Tuesday; * has optional Pro Guitar/Bass for an extra $1) • Shinedown – Bully • Shinedown – The Crow and the Butterfly • Shinedown – Second Chance *
...starting April 1, Harmonix is temporarily halting Wii DLC (as well as PS3 DLC in Europe) due to "mandatory changes being made to our DLC publishing arrangements." Existing DLC will still be available and they "hope to resume regular DLC service by this summer."
Personally, I wouldn't be holding my breath waiting for Wii DLC to come back. My prognosis for European PS3s is similar. For whatever reason, the Rock Band franchise gets way more support (read: sales) on the Xbox 360.
If you're still struggling with this and have held onto the game, maybe the patch they've just released will help? There's nothing specifically mentioning your problem, but maybe it's part of the memory leak issue?