Installing Fusion and creating a Windows virtual machine
For this article series, VMware Fusion was used as the virtualization software for Mac. So, before any virtual machines (Windows, Ubuntu / Linux) were created, Fusion software was installed on the Mac. Please refer to the following article for notes on installing Fusion on the Mac:
Installing Fusion on Mac OS X
Then a Windows Vista Ultimate virtual machine was created on the Mac with Fusion software. For notes on creating a Vista virtual machine on Mac, please refer to the following article:
Installing Windows on a Mac with Fusion
Then on top of that, Visual Studio was installed. Please refer to the following article for notes on that:
Installing Visual Studio on a Mac with Fusion
This article goes through using the Visual Studio created (as above) on a virtual machine.
The Size
Installing complete Visual Studio Professional takes about 4.4 GB of disk space. You would definitely want to have MSDN close by -- installing that would take up another 2.1 GB. So, installing Visual Studio 2008 Professional with help would take up about 6.5 GB of disk space.
If you created Windows Vista virtual machine with the default VMware settings, it would allocate 40 GB of disk space (and 1 GB RAM). So, 6.5 GB of disk space for Visual Studio 2008 is a good chunk, but well within the limits. Disk size for the Vista virtual machine can, of course, be increased dynamically.
Default Environment
When Visual Studio 2008 is started for the first time, you are asked to choose default settings for the development environment. In this case C# is chosen. If you are going to develop ASP.NET web sites, then Web Development Settings would be appropriate. If your projects are in VB (lot of Windows applications are developed in VB), then there are the VB settings. Still many many old applications don’t use .Net Framework at all -- they are developed using C++ and Win32 technologies -- perhaps Visual C++ settings would be appropriate there. General settings would be appropriate when not sure.
Figure 1. The Development Environment settings. This Visual Studio 2008 on a Vista virtual machine on an iMac can be used to develop Windows Forms applications.

The Visual Studio 2008 opens up fine inside Windows Vista Ultimate virtual machine. This Vista virtual machine does not support Aero (as the underlying VMware Fusion 2.01 does not support that); hence you will see the Visual Studio IDE in the Vista Basic user interface. This is not bad - you basically won’t see the glassy look on the windows.
Figure 2. Visual Studio 2008 inside a Vista virtual machine created with Fusion on a Mac. This iMac can be used to create ASP.NET web applications.

Sample Applications on Visual Studio inside a virtual machine
In the article below, a few sample applications for various environments are compiled and tested.
Command Line Applications
Command-line applications don’t have a Graphical User Interface. Here the results for C# command line program are shown in a “DOS” window. This command-line application written in C# is compiled from Visual Studio in a Windows virtual machine on a Mac.
Figure 3. A sample command line application written in C#. The Visual Studio here is running inside a Fusion created Vista virtual machine on a Mac

Windows Forms Applications
Windows Forms applications run on Windows (as opposed to Web). They have a Graphical user interface. Here a C# Windows Forms application is compiled from Visual Studio running on a Windows virtual machine on a Mac.
Figure 4. A sample Windows Forms application created with C# / Visual Studio on Vista virtual machine.

Web Applications
In this case, an ASP.NET / C# web application is compiled with Visual Studio and run locally on a Windows Vista Ultimate virtual machine created with VMware Fusion on a Mac.
Figure 5. A sample web application created with Visual Studio running inside a Vista virtual machine created with Fusion

Games
Following is a blackjack game written in C#. This was created using Card Game Starter Kit. This game is compiled and run from Visual Studio on a Windows virtual machine.
Figure 6. A blackjack game created with Card Game Starter Kit. Visual Studio and the compiled game are running inside a Vista virtual machine created with Fusion on a Mac.

Summary
Here the idea was to see if the basic types of applications can be created with Visual Studio 2008 running on a Windows Vista Ultimate virtual machine created with VMware Fusion virtualization software. As you can see above, command line programs, Windows Forms programs, games, and web programs can be created and run without any problems. I have not tested any programs requiring low-level hardware access in this scenario.
More Articles on Fusion
This article series on Fusion goes through a couple of virtual machines created with Windows Vista and Ubuntu operating systems. These articles also go through using popular applications like Microsoft Office, SQL Server, and Visual Studio on these virtual machines created with Fusion. They also discuss the pros and cons of virtual machines, graphics, sound, video, and Internet connections in them.
Article Series: Fusion on a Mac