Fui was downright bad at blocking in 2006 and was OK at best in 2007 (but whenever he was on the field he almost always got the ball--which 1. demonstrates the lack of coaching confidence in his blocking and 2. demonstrates a portion of why he didn't have great numbers last year, high ankle sprain aside. It's tough to run when the OC is telegraphing the play to the defense).
Manase gone will hurt a lot. Losing Joe Semanoff (who was a FANTASTIC blocker) was already bad, losing both starting full backs will certainly hurt. I have no idea what's going on with him, but it sounds like he's got some personal stuff to work out. Something like this can put a lot of strain on a new marriage (married in LA late last August just before the stop sign ticket incident--not a good way to start off).
I predict this costs us at least one spot in the preseason polls, at least initially.
I've never talked with Tonga, but I've watched him during and after games. I like his demeanor and his easy smile. I hope he can pull things together. I'm biased, but in the end I think his education will be a lot more important than his statline.