According to several Comcast representatives I have spoken to over the last few days, Comcast is now allowing customers in my service area (Eastern MA) to purchase a compatible eMTA.
I currently have the Arris TM822G and it works great! I can purchase the same model - new - on the Amazon website for a reasonable price.
Has anyone actually done this, and if so what has been your experience?
EDIT: I just now spoke with Comcast. Something to keep in mind: If you put your own equipment on Comcast's service, Comcast won't support the equipment. If the eMTA fails for any hardware-related reason, Comcast won't fix it or replace it. This is reasonable - it's not Comcast's modem.