Blizzard's confirmed to MTV that, while Diablo III will round off the plot from the first two games, there'll be more Diablo to come. This is probably very good news.
“We’re not saying this is the end of the Diablo universe, but we are trying to bring this storyline to a close,” said Diablo III lead designer Jay Wilson. “It’s not just Diablo III — we’ve got plans beyond.”
More through the link.