Ajax is the future, not Flash. Reason? Ajax does not require any plugins to be installed. All you need is a modern browser, which more people certainly have, than Flash. Also, you need to continuously update Flash - in fact, Macromedia just recently released a new version of Flash a few weeks ago.
Flash is still good for media such as audio and video (my preferred for things that move, such as games, for instance, but I like Quicktime for videos. Flash is probably one of the best for audio as well, though, since it doesn't freeze the browser

), so it won't be going anywhere anytime soon.
But more and more people will soon develop websites in Ajax rather than an entire website in Flash. Why? Because Flash is not indexable by search engines, since the text is contained in the Flash file. It will probably be possible to index the text one day, but for now, it is not. I'm sure Ajax has its own indexing problems, but not as many. Also, Flash is controlled by one company, and in this day and age, this is a no-no :p (At least, for the web

Of course there are certain times when a company is better than simply a method or an organization.)