MacBook Pro for Windows development via virtualization. Performance?

I wouldn't. I wouldn't touch that setup with a ten foot pole.

If you want to develop like that, partition the hard drive and use Boot Camp. I wouldn't be satisfied with the performance hit you're taking by running, essentially an operating system, an IDE, a web server, and a SQL server, all wrapped up inside VMWare Fusion.

Since you're buying the licences for everything to run, why not install and get the full performance from it?

I'm a longtime Windows admin/developer/gamer who recently purchased a MacBook Pro - 13", 4GB RAM. Only difference between what I have and what you're looking at is the CPU (mine's 2.2GHz). I've had no issues running VMWare or anything I throw at it. I'm actually VMing my Bootcamp partition. So essentially I have one Windows Bootcamp partition that I've wrapped up in VMWare. That way I can run it when I'm in OSX or boot to it, and I only have one instance of Windows and one set of Windows apps to manage. And to be perfectly honest, the only time I ever need to boot into it directly is for gaming (3D support).

As for performance, Win7 and VS are hogs, so I might consider going with more than 4gb of ram just so you can assign 2-3 to your Windows VM and still have an adequate supply for OSX. Otherwise I see no reason why what you're intending to do won't work. Rebooting back and forth between OSes is a pain - I definitely wouldn't go 100% bootcamp unless it's absolutely necessary.

I have a 2009 13" mac, and I have used it for windows-based web development using Virtualbox for almost a year now. It works perfectly. In fact it works so well that it has triggered a paradigm shift for me - I do almost all my work in virtual machines now, even on the windows machine at work.

I often run more than one virtual machine at the same time, and my main development VM has several SQL server instances running. I develop fairly heavy enterprise web applications in VS2008 and I have no problems with the performance. There is a penalty, but I honestly don't feel it is noticeable for web development. I'm sure I could measure it, but in my daily work I never even think about it. What I do think about is that when windowsupdate wants to reboot the VM, I just pop out of it and do something else for a minute. When the corporate antivirus bogs down my main VM, I minimise it and carry on wih something else.

The same VM's I run on the mac run just fine on my windows machine at work too. The convenience of having isolated, portable, easily-cloned machines for different tasks and different setups is just awesome. I would sacrifice a lot more performance than I actually do, just to have that.

The main performance killer is heavy IO, so keep your VM's on a separate physical disk from the host OS if you can and don't let Time Machine or Spotlight do anything on that disk.