So I find it very amusing to read this list of the most common Ajax mistakes - because lots of it reads like something that people have always bickered to be a problem of Flash sites:
- Breaking the back button
- Blinking and changing parts of the page unexpectedly
- Not using links one can pass to friends or bookmark
- Inventing new UI conventions
- Search bots not being able to index dynamic content
Hmm - maybe Robert Penner's good old back button workaround for Flash is also something that might work for you Ajax guys?