Java Desktop Apps

When considering a potential contract, I started wondering about how I would develop it. This shop I know is windows and there's very little chance they'd migrate to anything else so I started thinking, "Should I use C#?" It has certain benefits, to be sure. But just because I don't think they'll ever change operating systems, why should I limit them? Maybe they'll see the light and switch to Linux or OS X. So then what?

I considered using the Eclipse framework as a platform to crank out the app. That was an attractive option as it gives (at least according to the hype) near native speed on the desktop. But, then, eclipse also gets knocked for being slow on Linux even with SWT. On the other hand, I use IDEA as my IDE and it's as snappy as I could ask for. So when it comes down to it, I think I'll stick with Swing. It's a known quantity and available anywhere Java is. I don't really have to worry about deployment/installation issues like I would with the native components of a SWT app. The JDIC projects are starting to give Swing real muscle on the desktop. Now what would be really nice is a Swing based framework like Eclipse offers to build applications on top of. Maybe I could just port Eclipse to swing. :)