I saw this at the Picturehouse Central yesterday as it currently on re-release in cinemas (as well as on demand on Curzon Home Cinema). Curzon have said this will definitely be getting a Blu-ray release but they haven't announced when this will be yet.
As for the Criterion release - it's not a rumour as they announced earlier this year that they would be releasing it (well, in the US at least). Again, no release date confirmed as yet.
Such a great film by the way (I also saw it when it was released in UK cinemas in 2004).
My copy arrived from Amazon today. I'm looking forward to watching both discs at some point, once an annoying eye problem that I have is sorted. Right now, sub-titles would be a bit of a challenge -- grrrr.