the beta 3.6.6 includes mp4 and m4a The developers are working on the iTunes integration, including metadata. Here's the list:
asx;html;htm;xml;txt;pdf;ps;rtf;doc;tex;mp3;mp4;wa v;wax;au;aif;aiff;ra;ram;wma;wm;wmv;mp2v;mlv;mpa;m pv2;mid;midi;rmi;aifc;snd;mpg;mpeg;asf;qt;mov;avi; mpe;swf;dcr;gif;jpg;jpeg;jpe;png;tif;tiff;exe;zip; gz;gzip;hqx;tar;tgz;z;rmj;lqt;rar;ace;sit;smi;img; ogg;rm;bin;dmg;jve;nsv;med;mod;7z;iso;lwtp;pmf;m4a ;idx;bz2;sea;pf;arc;arj;bz;tbz;mime;taz;ua;toast;l it

(AC from /. ? If so--I enjoy your posts.)