A word of warning: I had very mixed success with this procedure, so it isn’t guaranteed to work. You might want to wait for a Vista-supported set of integration services.
Assuming you configured Vista VM with the network adapter and not the legacy network adapter, start Device Manager. You will get an Unknown Device message. Right-click the Unknown Device and select Update Driver Software. Make sure you choose to install Integration Services, which will mount Integration Services into the virtual machine DVD drive and allow access to the content. Next, manually browse for driver software and navigate to the Integration Services DVD architecture folder. Scan the folder and install the VMBus driver. Doing so will add support for both the network and updated interface elements.