I am currently part of a development team that is developing a new software for Windows Vista, and since I started at that company, I am using Vista.
A few things:
1) User Account Control is a pain the ass at the beginning, because that's when you're installing all your software. Afterwards, it probably won't bother you at all.
It's probably not very useful for a experienced and careful user behind a firewall, but I would keep it on if you're not the only one using the computer. In fact, I still left it on - no sense in taking unneccessary risks with your company machine.
2) Visual Studio 2005 works fine with Vista, at least if your developing with .NET (in my case 3.0, as we're using the Windows Presentation Framework for our software).
I haven't encountered any bigger problems with Visual Studio so far
3) Vista needs a lot of resources. In my case, it's probably mostly the fault of having to run Visual Studio 2005 developing a memory and graphics (even if only mostly 2d) intensive software, and running Novell Groupwise, the Document Explorer for the MSDN documentation, a browser and Open office parallel.
My computer started off with 512 MB RAM, and it really sucked. I quickly upgraded to 1 GB, and it was still slow, and I knew that I could take a short break whenever I would compile the whole code or even create a setup project.
Now I have 2 GB, and it's fine. (The improvement itself was amazing). I am finally happy, even though the cheap on-board Intel graphic card of the notebook isn't any good.
So, considering that you said you had 2 GB of RAM, I think you would be fine.
4)I don't have any experience with games under Vista, as this is my work PC.
5)I don't do much with the network, but I noticed that it's a lot easier to find the PCs in your networking environment. This was usually very difficult under XP or even earlier Windows versions.
6) Aero looks nice (though I had to turn off most effects when I had only 1 GB of RAM and my bad graphics card.
If I'll get a new computer, I will probably get Ista with it, though I am still considering a parallel installation of XP. But since I am planning to get a MacBook Pro next, all bets are off. I certainly will install a Windows parallel to it, but I don't know which one yet.
