Now to get some information about what "divx" actually is. Divx is an implementation of Mpeg4-ASP in the avi container. What the samsung devices has is the ability to play .avi/.divx(really the same thing) files. The G1 and other android phones can play the content of the file but have no real understanding of the container. Think of it this way. Divx is the box. Mpeg4-asp is the goodies insides. In the same way .MP4 is the box and mpeg4-asp again is the goodies inside. Currently most devices have no way to open that divx "box" to get to the goodies it can use inside. What would need to be done is to make some kind of libary using say NDK that opens the .avi/.divx and exposes the mpeg4-asp data to the media player.
What really bothers me is the general publics like of understanding of the difference between the Container, MKV, MP4, AVI, DIVX, OGG. And the codec, h.264(Mpeg4-AVC), divx/xvid(Mpeg4-ASP), theora, and vorbis