Dictation on my Mac isn't working either... I'm pretty sure it uses the same servers as Siri... can anyone confirm this on their end?
Confirmed here in Connecticut. I cannot get dictation to work on my iMac or MBA, both running Mountain Lion. It also does not work on my iPhone 4S or my wife's iPad 3. Siri is also not working on my iPhone 4S. Internet connections are strong on all devices using both 3G and Wifi.
Not working too. I did an iTunes restore and it still not responding. I'm starting to worry.
Why are you worried? It's happening to the majority of people.
Looks like Apple's updating the servers in prep for ios 6. No biggy.