Because Fraunhofer wouldn't (shouldn't) be breathing down your neck. (Technically, LAME, etc. are violating FhG's patents.) Other folks have claimed that the MP3 format has been tweaked within an inch of its life, while Vorbis is still fairly underdeveloped and already sounds as good as MP3 at similar bitrates. Ogg has builtin streaming metadata abilities, not just the hacked-on additions of ID3. Vorbis can support more than two channels (up to 255, IIRC), which, while not an issue for the empeg, as it can only play two channels, could a huge benefit for other players, especially when dealing with video. Also, it's possible to do what they refer to as ``bitrate scaling'', whereby frames can be edited out of a Vorbis file, reducing its bitrate without reencoding or generating double artifacts. This is very nice for being able to create reference sized Vorbis files and then chop them down to appropriate bitrates for different devices. I'm sure I've missed some stuff, but that's a good overview of why we should care.