We did the conversion from XP to Vista with our home network. One laptop used XP, the other Vista. Connection to the wireless network wasn't a problem. There may a few items that need to be addressed if it doesn't automatically connect. Follow the instructions from here:
http://www.vista4beginners.com/How-to-setup-a-wireless-connection
Overall, I like Vista, but it does have a few issues that make things more complicated then they need to be. Setting up a home network and file sharing being one of them.