Yes

No

Maybe just do it yourself

I think there might be limited interest, but here goes nothing. The following wifi module:

Product: http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/point-multipoint-rfmodules/xbee-wi-fi#overview
Manual: http://ftp1.digi.com/support/documentation/90002124_F.pdf
Size Spec: http://ftp1.digi.com/support/documentation/xbee_rpsma_mechanical_drawing.pdf

Works on the arduino wireless SD (and more than likely on the wireless shield).:

WirelessSD: http://arduino.cc/en/Main/ArduinoWirelessShield
Wireless: http://arduino.cc/en/Main/ArduinoWirelessProtoShield

I guess this also works now, since they added a better regulator:
XBee explorer: https://www.sparkfun.com/products/8687

I have never done any PCB work... ever. But i am a computer engineer, and i can teach myself. But maybe there is some interest. Hopefully there is a way to use the existing "footprint" and make a tiny-duino shield that will support this module. The biggest problem, is probably that the module is "big" and that the board would probably be slightly bigger than the standard 20mmx20mm tiny-duino boards that currently exist. But i guess that you can argue that the wireless shield will be the top level board and can be bigger/wider/whatever.

If this can't be done by the tiny-duino staff. Maybe somebody can point me in the right direction. I have already started setting up eagle and started moving only the circuitry that pertains to the module on the Wireless-SD board.

Hopefully i can get more info or a contact that i can bug for specifics on circuit design and component selection/setup.

Thanks

EDIT* added link for XBee explorer

The Xbee idea gets my vote