That's likely. But they are likely to be found by people that need them to solve a problem. The problem that meshnetworks try to solve is one that could use more minds on it. IMO this article has an unnecessarily defeatist attitude.
I know that that doesn't have the same romantic charm as a network that is completely owned and operated by everyday people, but ultimately it may be more effective. After all, a government agency could just as easily tap into an open mesh network and monitor traffic in a manner that's probably easier than it is for them to do now.
Ok, that might actually be deserved, but you get the point. That said, SOPA wouldn't block IPs. So, if you typed 173.255.237.82, you'd still get here. But, I agree, mesh networks might not be the solution. Maybe the best solution is a hybrid where your computer searches for the server over multiple networks. As long as the US government acts like it does, we need to keep trying.
(As a side note, it's a bit sad that we must resort to "sneaking around" in order to do completely legal things due to bogus laws.)