For those who worry about SA or any other way of 'switching it off': be assured that the largest usergroup of GPS has been proven in recent months to be quite supported by government and does not even move/navigate.
Banks nowadays use GPS to time transactions as a microsecond delay on a volatile stock/currency market can cost/bring in (dependend on the party) serious money.
As for Galileo/all others: the 28 (or maximum of 30 +2) satelites that the US can put up (a 5 bit ID seemed sufficient in the 70's) are often insufficient (try living above 60 lat). As the optimal RF spectrum for sending time-sensitive signals through the atmosphere is not to wide, it only takes some simple programming to include multiple pseudo-range sources (be it NAVSTAR/Galileo/Glonass/Some Geostationary stations)
i.e. Don't see Galileo as a competitor/the future (depending on view) see it as addition: 20+ satelites in view and you have continued navigation between high buildings. (in aviation, that would probably be combined with a prospect of having a chat on the merits of keeping above MSA in relation to keeping your licence)