Here's something that may be of interest.  Last night, I had a sneaky peek at the Zune's version of iTunes - although I don't have an actual Zune.  This isn't really intended for non-US countries but a small fib or two about where you live when installing/registering doesn't hurt.

This application appears to be a port of Windows Media Player (which I suspect is actually the engine behind the app) with a lot of the same functionality.  I only had time for a quick play but the big difference is that the Zune app recognises and plays the formats normally associated with iTunes.  I set the search folder to look at my media drive and it happily imported all my aac (M4a) tracks and mp4 (m4v) videos into the library.  I haven't checked the video content yet but the audio tracks play fine.  One review I've read says that the Zune app actually plays the audio better than iTunes (something I'm yet to doublecheck) through their native equalizers. 

On a sidenote, I know some would say that WMP doesn't play aac format because that is an Apple format, but that is incorrect.  This format was created as a possible successor to the mp3 format and was adopted by Apple as their default format for iTunes.  The aac format can be used on a wide variety of mainstream player applications, except for WMP.

The interesting thing (I think) is that this tool, which is basically a flash version of WMP, supports a wide range of formats whereas WMP is still stuck in the dark ages with limited format support.  In addition, the Zune tool has built-in XBox 360 streaming support - although I can't look into this as I don't have one (someone may try this and see if they can stream aac audio through).  If this is the case and Microsoft are going to keep WMP as-is going forward, why don't we just switch to Zune?

Don't get me wrong, I think iTunes is great but only as the file import and management tool), whereas I like WMP's playback and playlists but can't stand its ripping facility.  If the Zune app can play all my formats and I can still use iTunes for my iPod support, it would seem that this could be a winner.

I'll add more on this tool as I investigate it further.