SuperSync had a nice booth at last week's Macworld Expo 2011 conference. In addition to a demo of the software on our livestream, we also chatted with the developer about how SuperSync (which allows you to share and view multiple iTunes libraries across PCs and platforms) was doing lately. The most recent version is 4.01, a bug fix release that also added the ability to browse video across libraries and support for multiple formats.
SuperSync is not a cloud service; it's designed to control and view actual files across multiple computers rather than keep them up to date with a cloud server elsewhere. You can listen to music stored on other iTunes libraries with the app, but its main job is to keep everything current in all of the places it's installed on a network. Cloud syncing is something SuperSync is looking at, and backup storage is "one area we're going to keep looking at," according to the dev. For now, the purpose of SuperSync is to sync, not store. If Apple does announce a cloud-based iTunes solution this year, SuperSync will likely find a way to work outside of it.
Finally, I asked if the developer was looking at releasing SuperSync in the Mac App Store. It's being considered, though there are a few obstacles. Licensing is one; SuperSync sells two-license packs for US$25, and those are meant to be installed on multiple computers, possibly including a Windows PC. It's unclear how that would work on Apple's Mac App Store platform. Plus, the app "uses a lot of Java, so I'm not sure if we would qualify" for approval in the store in the current build. Still, getting featured by Apple would give the app a big advantage (a statement we heard from multiple developers last week), so it's a possibility, remote as it may be.