They certainly have the cash to finance such a massive undertaking. It could be step one in bypassing the cable monopolies, and maybe a precursor to their own voice network (blanket the US with WiFi calling maybe?). The impending FCC Net Neutrality ruling has got me hoping that someone will step forward and take this as a (long term) opportunity to shake up the market.
The real challenge is recreating the conduits and rights of way that the telephone companies have spent the last 100 years establishing. ATT's largest, most valuable asset is not the phone switches/networking gear or the copper in the ground or even the fiber they've laid over the last 20 years. It's the rights of way they control. Google's big battle with the incumbent phone companies is for access to right's of way and telephone poles. ATT is fighting tooth and nail to deny them access. Apple/Google would be better off purchasing a large cable company so you have a large network in place immediately rather than having to build one from scratch<p>Joe