I'm traveling right now and don't have access to all of my normal development tools but since I do have my handy MacBook I figured I would try a little experiment. Here's what I have set up right now:
Windows XP SP2, fully patched
I allocated 1GB of RAM to the VM for Windows XP and it worked great - plenty of headroom to run applications. I've said it before but it bears repeating since I know based on the comments that a few people that are Windows folks are considering trying out a Mac:
Windows runs really well, even on my lowly little MacBook. I did bump my memory up to 4GB, which I think is really important, but standard Windows applications (not games mind you - not even attempting that on a MacBook) work great.
To maximize screen real estate - really important on a MacBook - I run Windows XP in full screen mode. This still allows me to access spaces easily.
I was able to get Visual Studio 2008 Express installed without any problems. Early in the setup VS08 rebuilds much of it's library, so it's a chance to see the impact it has while running full bore. On my machine during peak compile times the CPU ran a steady 50% utilization. I jumped into other Mac applications, including Safari while it was working and experienced no noticeable degradation in performance.
Once I had VS08 up and running it ran really smoothly. I didn't stress it too much - just a couple of browser based applications - but it was able to load them up in IE and I could run through the debugger just fine. During these minimal tests the CPU barely broke a sweat.
To give you a sense of what's possible to run on a little MacBook, here I am using Spaces to run NetNewsWire, iTunes, iChat, Safari and finally a full screen Windows XP (lower right) with Visual Studio 2008 Express Edition loaded and running.
What's great about this is that I can rapidly switch between environments. Windows performance - even in a VM - is snappy. I notice a little window "tearing" when dragging windows quickly. I think that's probably a function of the way graphics are handled on a MacBook - no dedicated video card. The MacBook Pro does have a dedicated video card so it may not have this issue.
One thing I have noticed with the MacBook is that I do take a pretty decent CPU hit when viewing flash based sites. It's not nearly as bad with QuickTime video (interesting, huh?). When I speak to friends that have iMacs or Mac Pros they don't see any CPU hit when watching Flash based stuff.
Based on the results I've had I think I'm going to try loading up VS05 with my current product build into a VM and see what the performance is like. My project has gotten pretty large and uses some aftermarket controls for UI, so it will be a good test. I also am debugging my application using SQL Server Compact Edition so it's a pretty tall order.
On my Windows XP development box - a beast of a machine with an EVGA 680i mobo, Intel QX6700 processor, EVGA 8800GTX video and matched Corsair memory I take a significant CPU hit when VS05 decides to refactor my code while using certain design surfaces.
I have no doubt the MacBook will also strain under that burden but it will be interesting to see if it is still useable when that happens.