If a player/pair is first available on the Olympic Qualification waiting list, what is the likelyhood that he/she/they will be able to play in Athens? Very likely, somewhat likely, or very unlikely?

Not sure you can say like that, but I would say they have a good chance, as
At most tournaments major or minor there are at least one retirement from the beginning.

also, in the run up to a major tournament players will be training themselves to the limit in order to be at a peak during the competition. It is likely that many of the players will go beyond that limit and get injured. (witness lee wan wah, Ra, Ha, gao ling, taufik,all being previousley injured or still so at the present time-although I believe this is being precautionary on the terms of the top players not wanting to majorly injure themselves before the tournament, and that they are overuse injuries from the training load)

Being the olympics, I also think that people have "carried on playing" longer than they may otherwise have, just to have one last chance of winning the medal. The fact they are going longer will meaningna they are more susceptible for injury, as they are older (eg. Camilla, Kim, Ra, Ha, LDS/YYS, and other older players.)

Whatever the reasons may be whether it is close to olympics or not people get injured. It is a physically demanding sport.