One of the most important Spanish (and european) web of videogames, has published the next (This story has been translated by Google translator pages):
"No, there is no official confirmation by Blizzard at this moment, but the hints that show Diablo III will be his next project are becoming very obvious (remember that something similar happened in the months preceding announcement of StarCraft II).
The new signs are as follows: on the one hand it was learnt that the Blizzard acquired a few days ago the domain www.diabloiii.com.es (the proof: http://www.diabloiii.es/blog/wp-content/uploads/diabloiiicomes.PNG) and on the other hand, makes few hours web leads all Database Officer Fansites Blizzard (everything is done in it is authorized by Blizzard) has added a dedicated space for Diablo III (you have a snapshot of that site at the foot of the news).
No more to tell for now, everyone must draw their own conclusions. We will continue to report."