Like I mentioned earlier, every team loses good players every year. These were Jrs and UW had a very small Sr class (11 scholarship players). But depth is shaping up well and many young players have looked good in the rotation.
The defense should be good again next year. As good, better or worse? Can't say for sure. The offense needs to be better against the better opponents (USC and Alabama). We did start two Sophs and a TrFr on the O Line this year and lose one Sr Starter, but pretty much every one else returns.
I can give you a better breakdown of returning players/expected starters, but I don't want to bore the board with names few here have heard of before.