Wish I thought I could say he's wrong. I think he is, but he's also made a very solid case. The main problem with that case is that it is based on some suppositions that probably aren't true.
The main problems I see with his offensive outlook are at WR and OL. True, we don't have many WRs coming back who have caught a lot of balls recently. And we almost never did under Paul because we didn't throw much. But, if Patenaude's reaction is any indication, we have good WRs already and we'll have more coming in. I expect Camp and Sanders (provided he avoids injury) to have great years and Brown and Cottrell could as well. The speed and hands are there and, if that doesn't work, there always brute strength. I also don't have any real fears about the OL. Key seems to think we are still "a work in progress", but he also seems to think the talent is there. I think he's right; if you can learn to block in the spread option, the shotgun blocking schemes are nothing. Then all it takes is more work in the weight room and a willingness to carry more of a gut. Not a problem, imho. Oh, and I don't think QB will be an issue.
On D, unfortunately, I think he's right, especially after Brandon's death. Our one saving grace there is that Coach is as much a D specialist as Paul was an offensive one. I think we'll be a trifle thin up front, but we could be ok, if not great.
And all that said, I don't really have a clue about how good we'll be next year.