I have found a way to write and compile sidebar tiles without VS.NET Whidbey or the Longhorn SDK; so I decided to compile one of the sample tiles Microsoft has on the Longhorn Dev. Center.

Installation Instructions:
Extract the files to C:\SidebarTiles, and run Setup.cmd
Click Options on the sidebar and select News Feed.

To change the news feed, right click the tile and select News Feed Properties. Change the URL in the properties window to the desired news feed.