I recently created a new standalone C# library to abstract accessing a file system, including support for accessing the local file system and Windows Azure Blob Storage. The design was done so that it can be expanded to include SkyDrive, DropBox, and others.
One of the issues holding back Syrinx CS from running well on Windows Azure was that it was hard coded to use the local file system file images, files for downloads, and other content. The new file system library was a perfect match to help make Syrinx CS work properly on Azure.
This site as well as www.kusog.org are now running on Azure and the performance is working out well.