The one doesn't preclude the other. Heated gloves are pretty **** fantastic when you're really cold or riding a long way and the wind chill gets to work for 5-7-9 hours in a row. I'm rewiring my bike as we speak and one of those will be a dedicated cable/power outlet for heated Gerbing gloves.
Mechanical non-electric solutions would include wind deflectors - see
http://www.barkbusters.net/ and others - and really sturdy gloves, but circulation in the hands has sucked for me since I was a kid and I do need some cheating in the form of external heat.
That said, not even heated grips alone will do it, in my opinion. The wind deflectors are almost necessary even in combination with them because otherwise your palm will end up roasted and the top of your hand still remains frozen from wind chill.