I'm trying to make the case for upgrading my development machine to Windows 7 - I'm currently on Windows XP 32bit.
I've already identified the fact that moving to a 64bit OS should help performance by allowing me to max out the amount of RAM in my system.
But what other features new to Windows 7 are a boon to software developers?
On modern hardware, it is faster than both XP and Vista in just about every task -- booting, copying, launching programs. It also uses multicore CPUs more efficiently than XP.
I've also found that the search feature on the new Start menu saves a ton of time that I usually spent looking for files in XP.
As far as actual development goes, I know Eclipse has a native 64-bit version. Visual Studio doesn't have one though. In any case, 32 vs. 64 bit probably won't have any noticeable performance differences when you're using your IDE.
I've found the new Explorer and start menu search quite useful (most of this was already in Vista)
Also, it will encourage you to take advantage of Windows 7's new taskbar features in your programs.
It's my impression that many IT departments eschewed upgrading to Vista because of compatibility worries but will probably embrace Win7. That said it would behoove a programming shoppe to develop for Win7 simply because that market segment will grow. It's still early but i doubt Redmond would produce two stinkers in a row... Well, Win98 and Me were quite the tandem...
64bit will only really help you if you go beyond 4GB mark.
I don't know what you development platform is, but it would be probably fair to say that all new platforms will be thoroughly tested on Windows 7.
Also, you may want to read this article if you are interested in what Windows 7 gives you as a developer: