Sony apparently is moving ahead with the development of Infamous 2. A quick WHOIS search shows that Sony America recently purchased a domain for the title.
According to domaintools.com a quick search of domains comes up with infamous2thegame.com being purchased by Sony America on the 27th of April. The site resides on SCEA servers.
No official announcement has been made about the game at this time, maybe this could be a E3 announcement?
Stay with Playstatic for the latest on Infamous 2.