Yes, Diablo is in Diablo 3.
No. There are Diablo 3 teaser videos on the Blizzard website.
there is no god mode only overpowerd hacked gear for offline and open battle.net
Mephisto is mentioned, but does not appear 'in person' during Diablo 3.
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
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.
There are currently (as of August 2012) four Acts in Diablo 3, and all four are playable.
After a long wait, Diablo 3 was released on 15th May 2012.