Yes, read the article, but from my understanding MPEG-4 is designed to have the codecs be compatible with each other. This way one person who encodes using MPEG-4 codec #X can be decoded by MPEG-4 codec #Y.
Of course DivX ;-) isn't MPEG-4, but rather a hack turned legit for a MS' codec they submitted as a demo along with their ASF format to the MPEG-4 board, which was rejected. MS' version of the codec is currently used as the WMV7 codec.
So, help kill the FUD, and spread the word that the REAL MPEG-4 is on its way, and will be just as good, if not better than DivX ;-) for distributing online video. It will be cross-platform too!