It annoyed me no end that Sony decided not to give us the PS3 with the option to play DVD's as well as Blu-Ray. For that reason alone, nothing will make me switch to Blu-Ray for the forseeable future.
I have a large DVD collection and am not about to replace it all for something that basically gives us a slightly better picture (so what, I have no complaints about the picture I have on DVD) and a whole load of extra stuff that doesn't interest me in the least anyway.
Oh, and I forgot to mention the price of a Blu-ray! No chance of me paying the over the top prices when I can pick up brand new DVD's for under