I take the Thalys about 20 times a year and yes they are an operator of high speed trains and no they don't go to CDG. You can find out all about what Thalys does at Thalys.com
The Internet works about 80% of the time IME. It is quite disappointing when it doesn't work though. When it first started a couple of years or so ago, it was very fast. But now with so many people using it, it's kinda slow. But works just fine for email.