I'd consider the movie to already have a downer ending. Our access to space has been irreparably cut off and the destruction of a fair few satellites has cut off television, GPS and telecommunication services all over the world.
Increasingly, most of our telecommunications and entertainment data comes via the internet and cable TV, and not satellite. I once went to a talk by Frank Drake (head of SETI) who claimed that the Earth is getting 'dimmer' from the perspective of aliens listening to us. Famously, in Contact, aliens picked up Hitler opening the Berlin Olympics in the 1930s, and it's often joked that aliens must be sick of I Love Lucy in the 1950s and 60s.
But as the 21st century proceeds, most of humanity's chatter will be digital narrowcasting, rather than analogue broadcasting, so there's less leakage into space.
You're right - loss of GPS would suck. But if we can't launch anything anymore because of all the crap up there, we could replace space-based GPS with a ground based system (e.g. mobile phone antennae).
And yeah, having all that debris up there will make it impossible to launch anything e.g. probes to Mars. We'll need a giant orbiting Roomba to hoover it all up.
