No precedent is mostly true, though Kevin Mitnick might beg to differ, even if his circumstances were drastically different.
Trust me, if they catch whoever did this Valve's lawyers will make certain a precedent is set. This is very, very high profile, getting picked up on by every newspaper in the country. If they find someone to pin evidence to he'll get some very, very serious punishment. Odds are he'll end up bankrupt with at least a year of jailtime. Of course, 5 years later when he's allowed back on a computer he'll be making six figures in the digital security industry.
I'm all for massive jailtime for hacking. Cost someone money and you should pay. It's stealing, plain and simple, and one of the most costly, damaging ways to do it.