The US service was in beta for about 6 months I think but they probably had more issues to work out given it was the first launch region so I would be surprised if it was as long in the UK. As a side note I noticed that if you rent a game but don't start playing it immediately it states that you have 1 month from purchase to activate the 30 day rental so whenever the beta ends then I guess you could continue to access games for up to 2 months later depending on the last purchase date and time before the game is first launched.
