Yea right, even if you change the ports, you're not using randomized ports, and even if so, the ISPs can still detect who is running bitcoin nodes or other activity on their network and just say "sorry, we're turning off your connection because we do not support people laundering money with bitcoin", or whatever other excuse they want to make.  The corporations would even run their own nodes as a honeypot to sniff people out.  It's mostly a stupid argument since governments are far more likely to eradicate bitcoin through legislation than by pseudo-govt entities like Google, Comcast, or AT&T doing it under a corporate umbrella, but still, corporations can put a big dent into bitcoin viability if they want.