Although an attacker could exploit the hole to make calls, steal data, send text messages, and do basically anything that I can do with my iPhone, the researchers were kind and merely rendered it temporarily inoperable.
Here's what happened: While I was talking on the phone to Charlie Miller, his partner, Collin Mulliner, sent me a text message from his phone. One minute I'm talking to Miller and the next minute my phone is dead, and this time it's not AT&T's fault. After a few seconds it came back to life, but I was not able to make or receive calls until I rebooted.