It's all Famitsu's fault as next to Bethesda's E3 slot they put the word "secret" in their latest magazine issue. It's been 4 years since Oblivion.
The Official Xbox Magazine reported a while back that the next instalment to The Elder Scrolls was likely due to release in 2011, so a reveal now would be gravy indeed. The issue here is that Bethesda's Pete Hines said at their pre-E3 event in April that no major announcement from them is scheduled for the mega game feast in LA.
Have the top execs changed their mind? E3 2010 starts officially June 15th.