Yes, Diablo is in Diablo 3.
There are no plans to make a Diablo movie.
Mephisto is mentioned, but does not appear 'in person' during Diablo 3.
Never heard of such a thing.
Diablo 3 is out now, it was released on the 15th of May 2012.
No, there is no pirate class in Diablo 3. If you mean to pirate the game, you cannot do that either.
diablo 1 is about 100mb diablo about 800mb and diablo 2 expansion another about 800mb
El Diablo was the name of the dobie, it's spanish for the devil!
It's been over 13 years since Diablo 2 was a true Hype, so this would give you a perfect reason not to worry if Diablo 3 would be your 1st Diablo game experience.
Diablo 3 was released on May 15, 2012.
The requirements can be found at the official Diablo III website.
You can purchase Diablo 3 for Mac computers online at the Diablo website; the hard copy version can also be purchased at most computer game stores.