To summarise, ASUS has entered the arena of PC audio with an impressive feature laden product that tries to cover a very wide spectrum of audio from recording/mastering, to surround media, to games; which is no mean feat considering the prices of even the most basic specialty solutions out there.
The Xonar has an impressive spec list for the market its intended for and features a plethora of connection possibilities no-matter what your requirement. On top of this, retail versions will feature a comprehensive software bundle to complement the hardware on the card.
It must also be made clear that there are cheaper options out there for gamers or movie buffs etc. who don't wish to do it all and maybe are only light users, but someone wishing to buy one sound card that will theoretically handle all their audio requirements for years to come should make the Xonar a serious consideration.