The video was uploaded to Ms Lee's YouTube account, and was apparently taken at the New York Comic Con, a convention at which EA BioWare is certainly in attendance and showing off Omega concept art.
We've reached out EA BioWare for confirmation of these details and further information.
Update: A post on the BioWare blog confirms the details. The Omega DLC is coming to PC, PSN, and XBLM on November 27 for $14.99 or 1200 MSP. PS3 owners in Europe will have to wait until November 28 for the DLC to hit the continent. The blog post reads:
"Disturbing reports from the Citadel suggest that something big is about to go down. If our Intel is accurate, Aria is on the move. This was anticipated, as we did not expect her to sit idly by while Cerberus ran roughshod over Omega. With her biotic capabilities and well-documented mean streak, what happens next won't be pretty. Our informants believe that Aria intends to seek out Commander Shepard for assistance. We are aware of the Commander's ties to Aria, but are unclear about how deep they run. What we do know is that Aria will be relentless in her fight to take back Omega, and with the Commander at her side, she may very well be unstoppable."The video linked above has now been made private.