I found the following in the MP3 Wiki..

In spite of the patent restrictions, the perpetuation of the MP3 format continues; the reasons for this appear to be the network effectshttp://en.wikipedia.org/wiki/Network_effectcaused by:

- familiarity with the format, - the large quantity of music now available in the MP3 format, - the wide variety of existing software and hardware that takes advantage of the file format, - the lack of DRMhttp://en.wikipedia.org/wiki/Digital_Rights_Managementrestrictions, which makes MP3 files easy to edit, copy and distribute over networks, - the majority of home users not knowing or not caring about the patents controversy, who often do not consider such legal issues in choosing their music format for personal use.

Well, i dont know how many of us know this....