The latest list (»www3.tivo.com/products/source/ca···_comcast) now shows "Western Washington*" replacing only "Seattle/Tacoma, WA" and "Southwest WA" plus a few more areas now have asterisks (*).
Here's the list of areas as of this morning:
New England/Boston Area*
San Francisco Bay Area
Santa Barbara, CA
Kansas City, MO*
* XFINITY On Demand is currently not available in all areas of this region.