They're just slapping the logo up there because Divx is a subset of Xvid, which is a subset of MPEG4.
DivX a subset of XviD? How do you figure? Currently DivX has nothing to do with XviD, beyond the fact that they both conform to the Advanced Simple Profile (ASP), i.e. ISO 14496-2 MPEG4 sub-standard.
If you trace XviD's roots you will find that it is evolved from the original DivX;-) 3.11 Alpha codec, which itself was a Microsoft MPEG4 ASP codec that was hacked by "Gej" to support output to the AVI container. Oddly enough, the current versions of DivX have nothing to do with the original DivX;-) 3.11 Alpha codec; but was done from scratch.
Anyway, I have a Philips DVP642 and it has played everything I have thrown at it so far (other than the audio stream of a WMV [WMA]) and I am perfectly satisfied with it. WMV's are irrelevant for the most part to me anyway; the vast majority of my stuff is XviD, with which it has no problems. It also plays DivX;-) 3.11 Alpha with no problems, and since most 3.11 Alpha files were encoded with Nandub, they have VBR audio, which is a hack to the AVI format which doesn't technically support VBR audio; but it has no problems with that either. Awesome player, especially for $55 at the local Super Wal-Mart.