I've been using MediaMonkey since 2005. Version 3 fills all of my needs but on a whim I decided to download the latest beta version of MediaMonkey4. The big news is it now supports video (including HD .mkv) but I have no interest in that. I was however happy to see it can now be used as a server. I have a couple of old Roku SoundBridges (native Apple Lossless support) so I pointed it at my M4A Lossless library, and it works flawlessly (and fast). The thing I like best is besides the usual browse by Artist, Genre, Playlist etc., you can browse by year. It's broken down by decade but you can select individual years as well (I've been using it to get to know some of my 2011 albums better by playing all 2011 releases randomly). Very cool and something no other server software I've tried can do (WMC2, iTunes, Firefly, Slim, and Asset). You can also browse by location, which is useful if you have multiple music libraries.

I haven't come across any bugs yet so it must be getting close to release.

The default skin is different from this screenshot but I prefer the Version 3-style skin.