M3-27 is originally set to take place on May 1, but it is likely that there'll be changes. The official website for M3 mentions that it will make an announcement later on.
Lotus root Orchestra's Yuka has posted full version tracks of her latest work, Seventh Blood Vampire, on MySpace from Mar 19-21. The CD, along with the accompanying comic, was originally set to be released at Haru Comi on March 20, but the event was cancelled. The CD and the doujinshi would likely be released at M3-27 instead. Yuka asks that you donate to Japan Red Cross after you listen to the songs.
Edited on Mar 27: The full version tracks are no longer available. If you like the songs, wait for the CD instead.