The owner of the website fourthirdsphoto.com had the chance to make an interview to Mr. Watanabe. You can read all of it here:
http://news.fourthirdsphoto.com//node/14
The most important statements are:
1) We are planning a successor to the Olympus E-420 and it will be different. (that was all he had to say about that one.)
2) Yes (we are planning to introduce prime lens), but it is difficult to prioritize which ones to make first.
3) No release of either a camera or lens µ4/3 (Micro four thirds) road map.
P.s.: I’m waiting for news about the Olympus E-450 release date. Do YOU know something? ;)