Installing the Mog-o-matic software is a double-edged sword. On one hand, it's yet another application running in your system tray. On the other, you can upload your listening habits and tastes without any additional work or need to replace your current jukebox solution. We'd like to see these types of services move toward a Web-based process that scans your music library's database files and updates without the need for software. Although if you're concerned about personal privacy, this isn't likely to sound appealing either.
On a side-note, Mog's servers seem to be getting slammed at the moment, so expect some slowness while browsing the new features.
Related: StumbleUpon's music channel, iLike.