Earlier quoted context omitted.
It's a victory, yes, but probably not huge. The majority opinion, written by Scalia, takes the narrowest of views: that placing a GPS device is a "search", and as such, subject to the limitations set out by the 4th Amendment. In a (concurring) opinion, Justice Sotomayor agrees with that narrow view, but she asks what will happen when the Government doesn't need to place an actual physical device in one's car in order…
In my own opinion (IANAL), the "tracking is a "search"" view does not imply that there needs to be a physical device. So tracking a vehicle (using technology) in any other way is also a "search".
The greatest concern would be when surveillance satellites could be used to track cars inside a city. Or using CCTV traffic cameras for a live-tracking of tagged license plates. The question is would this tracking actually constitute a search. Because a warrant doesn't have to be issued for an undercover cop to follow a car, only probable cause. So does 'probable cause' extend to digital tracking through a CCTV grid, satellite or combination? That's where it gets creepy to me, because IMO this likely won't constitute a search.