Ok, so, I'm inclined to believe Muse are playing at Stubb's in Austin during SXSW this Thursday sometime during the day. Going off of this:
https://twitter.com/Andylanger/status/310968072901103616
+ This (a concert featuring Pat Green being thrown for the Final Four Concert Series, where Muse is performing in April. I feel positive this is where they'll be at on Thursday):
http://1iota.com/show/view/Road_to_the_Final_Four_Concert_Series_presented_by_Coke_Zero
+ Dead Sara being in town/playing a showcase that day (can't find the website for the party they're playing currently, but they are playing a showcase/party/event that day)
+ Muse having the day off and already being in TX during the week. As well as playing at Stubb's during SXSW in years past of course.
Grain of salt and can be a stretch though. We'll see what happens.