A recent job posting from Blizzard on Gamasutra indicates that Diablo III may actually be making its way to consoles. The newest posting shows that Blizzard is currently looking for a "Console Network Senior Software Engineer."
Diablo III director Jay Wilson has said that the team has been looking into bringing the game to consoles, but is hesitant to discuss it further until he's sure it's happening. Since then, rumors regarding the game's potential release on consoles has persisted, with job postings like this one occaisionally adding fuel to the fire.
The fact that the word "console" is in the title is probably enough for a lot of people. However, if you're still skeptical, the posting describes the engineer's role as being "responsible for ensuring the best implementation of sophisticated networking systems on consoles."
The listing also says that qualified candidates should have worked on at least one AAA game for Xbox 360 or PS3. While it's the flimsiest of evidence, that could give you a little insight as to what platforms Blizzard has been working with.
Plus, they said "console" three times! That means they have to making Diablo III for something other than PC, right?
Until Blizzard announces something, this is all speculation, but every time one of these jobs pops up, it seems more and more likely that console gamers will get play Diablo III too.