Danny Rubin, Tim Minchin and Matthew Warchus (the latter two past collabararors on Matilda the Musical), with a superbly performing ensemble, utterly knock Groundhog Day out of the park.
If you can get tickets for the run at the Old Vic in London, I absolutely recommend it. If not, I'd be very surprised if this isn't transferring to the West End or Broadway sometime soon. (Warchus is very open about the fact that the 10 week run at the Old Vic is "a test run", and one it passes with flying colours)
Almost perfectly constructed, warm, funny and hugely positive, a beautiful, fantastic piece of theatre, that takes the source material and makes it better.
(@Sanjay and I saw it this evening, and both of us had big grins on our faces at the end)