Russ makes the comment of using Microsoft tools as they're always the latest etc. This may be true, but I've yet to run into problems using Delphi and as Jan states, there's heaps of examples for Delphi out there. I've found a certain 'stuffiness' when trying to find Microsoft examples - Delphi forums seem to be a lot 'friendlier'. Then try to look for Windows CE stuff!

Also, there's the endless march of new operating systems - like the new Vista. You're sorta forced to update your whole toolset to conform with the new operating system so you have to revisit your whole code base to upgrade then go through a whole new test regime. So just when you've got your product stable, the new OS comes out and its back for another round. Great for keeping programmers employed! So to avoid this continuous change, the thought is to go WEB2.0 based. That way you can avoid using Microsoft tools if you so desire and can run on anything that has a web browser - like a mobile phone, PDA, Linux...
The reality might not be quite as rosy as the picture I'm trying to paint but at least you're trying to target something that has base functionality that (hopefully) won't change.