Windows Vista Home Premium OEM 64 bit on Macbook Pro with VMware Fusion 2.0

I just installed Windows Vista Premium OEM 64 bit through Boot Camp and everything just worked without problems. Well until I tried starting the Boot Camp partition from VMware Fusion 2.0 (116369) and it started complaining about a missing ethernet controller driver and a missing basic system driver.
After installing VMware tools and restarting the virtual image it found new hardware and installed the matching VMware drivers. Only problem was that the ethernet driver wasn't found. I then tried installing it manually but without luck and I finally had to contact VMware support. To my surprise the OEM version of Vista isn't supported in Fusion 2.0 and therefore they could not guarantee that it would work...
Well after some communication back and forth they gave me a very simple solution that solved the problem:

VMware Fusion Team does not recommend using OEM install as Guest OS in VMware Fusion. Please go through the following KB article for the same. This is applicable for all VMware Products.

http://kb.vmware.com/kb/1116

Typically, OEM install CDs are designed to place an operating system onto a PC with the factory configuration and defaults specific to that vendor.

I would still like to outreach and help you out, but we would like to remind you that the following suggestions may or may not help you out, even if the suggested solutions works, it might fail under several unpredictable conditions.

If the recommended solution fails then, I would recommend you to install Guest OS using retail/Volume version of Windows OS in Fusion. However it may be possible to install OEM license version of Windows OS, which may or may not lead to unexpected behavior on your system.

I am suggesting you to change "Ethernet Controller" and then install Ethernet driver by going through the below instructions.

1. Power off Virtual Machine
2. Quit VMware Fusion Application
3. Navigate to Virtual Machine folder

Default path for Virtual Machine: Macintosh HD/Users/User Name/Documents/Virtual Machines/Virtual Machine

4. Select Virtual Machine and right click on Virtual Machine
5. Click on "Show Package Contents"
6. Select and open ".vmx" file using a standard text editor
7. Add following parameter to the configuration file

ethernet0.virtualDev = "e1000"

8. Save the modified Configuration file
9. Power on Virtual Machine and check

After adding above parameter in the .vmx file, please download the driver for Intel "e1000" network adapter for Windows Vista from below URL and install the same.

http://support.intel.com/support/network/sb/cs-006120.htm

Thank you for your continued interest with VMware Fusion. We appreciate your valuable inputs shared with us so far.

As my Vista isn't a real VMware image but a Boot Camp partition, the path for the virtual machine was a little different:
/Users/username/Library/Application Support/VMware Fusion/Virtual Machines/Boot Camp/%2Fdev%2Fdisk0/Boot Camp partition.vmwarevm/Boot Camp partition.vmx

After adding the "e1000-line" the network worked after starting the image and I did not need to install the Intel driver described in the last step.

I must say that I am very satisfied with the highly professional and comitted support from the VMware supporter that handled my issue!