Power Supply Facts
The EP121 uses a customized version of the Innergie mCube Lite power supply. The major difference between the two (other than product logo) is the EP121 has a single DC input connector designed solely for the slate while the mCube Lite comes with a set of interchangeable connectors. I have submitted a query to Innergie to see if they include a DC connector that is compatible with the EP121. I will update this post when I hear back. At the time of this writing, the price is listed at $79.99.
Details are here:
Update 2: Innergie has yet to reply but as per the user comment below, it is confirmed that Asus US is now selling EP121 power supplies.