well my thoughts are in your last post
viewtopic.php?f=6&t=1852wifiphones are great if for some reason you dont own a cell phone, they however are not stable skype of all things isnt that great, vonnage and clearwire seem to have better networks as they also have more robust e-911 services.
if your gonna have a home phone might as well just pay ma-bell 9$ a month for a 911 only phone and use your cell plan for everything else - lot more reliable
but to comment on this technology... dont do it, why? 802.11 coverage from consumer AP (dlink linksys netgear) is far from good for full coverage in a 2 story home. So now you have a phone that will cut out in areas of your house...you need another AP (a whole nother issue for the consumer)
not to mention all the overhead that you have from just the voice 802 headers/encryption,IP stack. I believe the comcast and vonnage units are analog/digital handhelds and the base is the mux/modem for the IP.