This is only a guess about the testing for Demon Summoning, but if they follow the same track that they did for Dual Pistols (which the devs said they really liked the focused testing). I would guess that beta testing for Demon Summoning will start either next week (unlikely) or the first week of March.
Considering that Going Rogue goes up for presale in early March (
http://boards.cityofheroes.com/showthread.php?t=210328 ) at which time Dual Pistols will be available on the Live Servers. So if they schedule the same time frame for Demon Summoning testing (one month) and Demon Summoning is planned for release in April on the Live Servers then March will be the test month.
Just a humble guess from me and for some reason it sounds to me like I rambled on way way too much... I think I need more coffee >_<
