Low latency, no. Why? Here's how a satellite internet service works:
You have a dish on your house which has a transceiver. It shoots a data packet to the satellite, which bounces it back to the NOC (Network Operations Center) where it connects to the internet backbone (in most cases currently, owned by large corporations, in this case let's assume SpaceX builds their own). That NOC then sends data back to the satelite, which redirects it back to earth, where your dish captures it, and then to your modrm, to your PC. So: PC -> Modem -> Transmitter -> Satelite -> NOC -> 'Internet' (let's say Google's servers) -> NOC -> Satellite -> Receiver -> Modem -> PC.
Currently, most satellites orbit the earth in a stable orbit about 130k or so I think. Why? Because from there the satelite can cover a wide area (ie: half of the northern hemisphere). The signal time between the earth and the satellite is about 500ms, so double it since you need to transmit AND receive. Now you're talking about 1000ms (or 1s). Thats gross.
What spacex wants to do seems to be to have a much closer cluster of satelites (75k, so half the distance = 250ms), but you'd either need more NOC's on the ground, or the satellites have to pass the request through a bunch of them and back again (which adds latency).
Every time that signal is retransmitted, you're going to lose data, which means retransmitting through the whole chain again. At best, I can imagine a 500ms ping. Which is still awful.
ON TOP OF THAT: If you have electromagnetic interference in the atmosphere from, say, a thunderstorm, or the dish is covered in snow, or the NOC is subject to weather... Your internet connection is affected at best, offline entirely at worst. Your dish gets a good blast of wind and shifts a few degrees? Fucked. Have roofing work done? Gotta get that bad boy repointed and locked back in.
Besides that, the other problem is that satelite, once up there, is there for good. Nobody's going up there to upgrade the tech on it, so it ages into obsolescence pretty quick. Spacex solves that by just destroying the satellite on its own and constantly launching more. That's actually s really good solution... If you own the company launching all these rockets! Other companies trying to do this probably won't have that benefit.
In the end, no satellite system is ever going to be able to compete with a ground based system for latency and service reliability. Satellite internet might work well for remote locations, or for those people who just want to check email and Facebook, but anyone using it for streaming video, gaming, communications, basically anything needing large data and/or low latency is going to be using ground-based systems.