It sees it all but can't play it all. For one it can't play wmv files. At least it couldnt last time I tried and I doubt its changed since I cant see microsoft ever licensing the format to them or however that works. You may be able to download other things to do it since I know you can run linux on the PS3 but the 360 has handled all my media so well naturally that I've never had the need to look into my PS3 media capabilities more. Most of everything I play though is mp3s and wmvs so as soon as the PS3 couldnt do that(wmvs) I sort of stopped messing with it.

Though I must admit I play the 360 a helluva lot more so I know more about what it can do.