They may never reach those standards but they must improve, mustn't they?
I think the market is very healthy, just different.
For example, I believe per-sale opportunties are at least as strong as they ever were. Some other types of opportunities (like CPM based banner advertising) are almost certainly not once they once were.
If I was to guess
I think that Per-sale (and some per-lead programs) will continue to improve as there is increased competition for affiliates who actually deliver sales
I think that CPMs across the board will not go back. I think that advertisers will be looking for smarter ways to spend their money, either by more sophisticated targetting, by deeper integration into web sites, being more selective on where to spend the money etc.
I think that the 1999 market was unique, because (1) you had a huge venture capital bubble supporting it, (2) many companies with apparently no immediate desire to make a profit but a rather a desire to build their name in anticipation of a future hockey-stick effect, (3) compared to now, probably less sites and surfers to pursue, and (4) a whole bunch of web surfers who had not become relatively immune to banner ads and had not learned how to close popups in microseconds. Frankly I would be surprised (but not at all upset!) if any of the subsequent trends reverse themselves.