Some time ago, Apple started a list of products that would run "natively" (either Carbon or Cocoa) for Mac OS X. As the release date draws closer, we thought it would be a good time to remind you of this list, and to point out that applications for the forthcoming OS appear to be plentiful. Products from nearly every software category, ranging from games to Internet to productivity, are in the works for OS X. According to Apple: Developers are hard at work building hundreds of applications to take advantage of powerful new Mac OS X features such as memory protection and preemptive multitasking. See the complete Built for Mac OS X list.
To get an idea of what to expect, application wise, when OS X ships take a look at the complete Built for OS X list.