Windows CE seems to be gradually losing what little market share it has, while the Palm platform keeps expanding. The next version of Windows CE, code-named "Rapier," is supposed to be much easier to use. However, it apparantly is not.
One developer that writes programs for both the Palm OS platform and for WinCE said "They've still screwed it up," and that that Microsoft needs to get rid of the Start menu. It also does not help when manufacturers such as Philips decide to stop making WinCE devices because of poor sales.
By the end of the year, the Palm OS is expected to have 80% of the palm-size market, with Microsoft still sitting at 13%.
For more, read the ZDNet news article.