If you want a cool DVD jukebox for your ripped DVD's, there's a neat little hack to make a DVD gallery in your Vista MCE.
Go to channel8.msdn.com for the guide.
If you need covers for the collection cdcovers.cc is a good source.
If you want to add extra information about the movies there's also a solution for that. Go to avsforum.com and download DVD Library Manager. Personally i prefer the information from IMDB.