It's pointless comparing 3G or any other existing European wireless networking infrastructure with what Google have planned unless there is a similar area of the spectrum available for Google to purchase Europe-wide and to be honest, the chances of that are slim to non existant.

Assuming Google do buy the 700Mhz spectrum on offer, I can't see Google expanding beyond the US market due to insufficient spectrum available world wide. That, or Google will be forced to develop hardware using frequencies specific to each region (and even country) which gets seriously expensive on the hardware front, let alone purchasing the frequencies in the first place! Multiple frequencies is also "messy" for the consumer.

What Google are trying to do sounds interesting, but I can't see it having any impact in Europe (or anywhere else outside of the US) anytime soon.