GameSpot's Most Popular games list is reporting that Diablo 3 's release date is set at December 31 2008.
This detail contradicts Rob Pardo's statement that the game would only be released in a year to a year and a half from now. But considering that Diablo 3 has been in development for 4 years, it could be entirely possible.
I'm 100% sure that this is just a temporary placeholder.
I bet that it's going to be changed to 'TBA' very soon.
Blizzard keeps it's "initial projected" release dates about as often as a drunk keeps 20 dollars in an ABC store.
Sorry, but you can parous their database and see plenty of incorrect release dates. This is just a guess on their part.
There's no way it comes out this year. Starcraft II and Wrath of the Litch King have to come out first. I doubt Blizzard would release two brand new games and one expansion back for its big IP's. A year to a year and a half is optimistic in my opinion.
It won't be out this year, it's got another year of developement, as has already been stated.