At the moment the latest version of Flash you can buy is "Macromedia Flash MX 2004", However you can pre order "macromedia Flash Basic/Professional 8" which i prosume is coming out soon.

It is a great program for creating animations, games and other things, however it's quite confusing to start with. I wouldn't recommend any other programs though, because it's the best for the job!

www.macromedia.com