Good article. I agree with your observations.
I do not trust previews/reviews to do more than point out features of Fallout 3. Reviewers can be bought. Even if honest, opinions of "goodness" and "badness" are in the eyes of the beholder -- so I will not place much credence in those. I will reserve my own opinion as to how good or bad Fallout 3 is until after I've played it myself.
When playing, sometimes I need to stop, sit back, and think about how to play a game to get the most out of it. That takes time most reviewers do not have, I imagine. Moreover, adapting to a game is a direction most will not take, I imagine. Rather, it is either "good" or "bad" based on first impressions. I think reviewers tend to err on the side of "good" if a game has been hyped enough.
With Oblivion, I had to restart after my first 15 hours because at first I was playing it "wrong" -- I had to adapt to its idiosyncrasies and play it on its own terms. I played the first 100 hours with the as-released game. Then, I put in all the major mods at the same time (and added my own little mod) and played 300 more hours (now I am played out). I put Oblivion in my all time top 5 or 6 crpg -- but, that took some effort on my part to understand how to get the most out of it -- time reviewers and other players may not have had to spend.
I imagine Fallout 3 will be the same. I will need to play it a while and adapt my play style a bit to get the most out of it -- maybe restart after a few hours. But, I will not base my "buy" or "not buy" decision on how reviewers/others liked it -- rather, I will take my chances if it seems to have a good mix of features (which it does).