From what I remember of early reviews of the FX5200 non-ultra, it underperforms the 9000 non-pro on most game demos (without AA/AF). So by that reasoning, the 9200 non-pro should also be a match for it there. Similarly, the 9000 pro had a slight edge over the 5200 ultra (but again, newer drivers may have changed that). Regardless, I also agree that the 8500/9100 core is clearly superior for non-AA/AF modes.
Of course, one of the advantages for the 5200 is its AA/AF ability, but its debatable who would actually want to use it. Of the two, AF is probably the most likely thing people will turn on. The early 5200s took about a 20% hit for AF, apparently, but I know the 8500 only takes about a 10% hit (of course, the 5200 AF is likely to be superior in quality). Again, newer drivers may have helped the 5200 ... not sure on that one.
So, to summarize, hard to choose between the 9200/5200 ... but I would still go for a 8500/9100 for the same price, or the Ti4200 if close enough (around here, they still cost twice as much as the 9100s!).
Where does good judgement come from? Experience. Where does experience come from? Bad judgement.