I had the same problem Wed night, and have managed to solve it.
I followed Apple's "Unable to restore" guidelines:
http://support.apple.com/kb/HT1808
I followed them to the letter.
It took a while (in part due to my network and how I have my iTunes library stored), but it did a complete reset on the phone, and then reloaded my data (I had a backup on iTunes from an earlier sync).
Interestingly, it restored me to OS 3. Sadly, I now have the "grayed out" wifi and bluetooth problem, but it's an improvement over being locked out entirely.
One note: at one point during the forced recovery, my iPhone displayed the "emergency calls only screen" screen again ... but it then chimed twice and continued without a problem.
Hope this helps.