the music player (Music sounds better on the Nokia 808 than on the Lumia due to dolby sorround. Plus there is an equalizer) and the better connectivity options.
As a regular Headfier that has bucket loads of 100-400 euros in-ears and owns 808, 808 has one of the best sound qualities via 3.5mm than any other phone and it doesn't really have anything to do with dolby , but simply the chip inside. N8 was famous in the HiFi circles as well.
That custom hardware that Nokia uses on Symbian phones is a curse and a blessing in a same time.
I kind of a fear for that on Windows Phone. People seem to forget that if Microsoft limits manufacturers using only one system on chip, Nokia can't either bring many of it's patent goodies and hardware innovations to Windows Phone.
You can't just simply port some features over.