Dragon Age: Origins -- Awakening (Xbox 360): Please settle once and for all, DA:O needed?

I've been seeing nothing but conflicting stories about this expansion. Is the original Origins disc needed to play this? Here on Goozex it says no, Bioware's webpage says yes, and different box arts I have seen say yes and no.

Does anyone have this who could give me a final answer? I'd like to trade of my copy of DA:O if possible.

When I put in my DA:O Awakening disc into my 360, it found my DA:O Save file and account through EA/Bioware and asked me to select the Expansion. It never had me put the DA: O disc into my 360 at any point.

If you buy the Expansion as DLC from XBL, you will need the DA:O disc to play it.

Thanks!~