Contactless limit increase

I've seen reference to the fact that the contactless card limit is being increased from £30 to £45 from 1st April (Wednesday) - but initially only in "selected stores". Does anyone know any further details?
http://www.gripsky.co.uk/vocalvoices/
http://www.gripsky.co.uk/vocalvoices/viewtopic.php?f=5&t=15823
medsec222 wrote:I go in with my own Delta taxi shopping bag Frank, I just put stuff in it like a shoplifter and unload it when I get to the checkout. Not perfect ...