Hi - I just read that LINQ is going to be integrated with VS "Orcas". You can watch the video posted by Scott here - http://www.scottgu.com/blogposts/video/linqtalk1.wmv or you can download it from here - http://www.scottgu.com/blogposts/video/linqtalk1.zip
Note that i made while reading was that you can use LINQ to write queries against varied multiple data sources like - SQL database, XML files or even the web service call.
You can check this implementation that supports LINQ calls to Amazon web service.
Cheers - D