Web vs. WinForms
I believe many people are writing web applications for the wrong reasons. The most common reason for choosing a Web application over a WinForms application is - "with a Web application, deployment and version updates aren't required on the client's computer"
Or even worse - "build a web front-end, because that's what everyone else is doing." How's that for teenage mentality? I've heard this from (non-technical) managers a number of times.
Not having to worry about deployment and updates is great, but that's not a good enough reason to choose Web over WinForms. Giving a WinForms application the ability to update itself is actually very easy. Check out this article on TheServerSide to see how No-Touch deployment, the Updater Application Block and Click-Once(.NET2) can be used. That's not one, but three, different ways to handle automatic updates!
WinForms is such a rich, powerful platform. I think it's really important to use the right technology for the job. If you're writing a Web application only because it's the cool thing to do and it'll take care of updates, think about it… maybe it could do better as a WinForms app?