Talking on Famitsu, SCE CEO Hiroshi Kawano during a Q&A session told the forum that the next Game Heaven event won't be too long from now, and promised some big names for it, none of which he can reveal.
Read into that what you will. I think July is now unlikely, and with TGS in September that leaves August as a decent time to set out the agenda for the big show. It might happen to coincide with Gamescom, so the Japanese don't feel left out if Sony decides to unveil some new stuff over here. What those games are is the tantalising question, any guesses except the bleedin' obvious?