iPhone: WiFi, Bluetooth and cellular network not working
Wow. Seems like the modem/baseband part is gone wrong. Try rebooting the phone. If still not working - backup your information (from iTunes) and try a restore to factory settings (I'm assuming a factory unlocked phone, no JB). If this doesn't help - probably it's a hardware failure.

About the IMEI blockage - no, it's not the case.