The Apple TV 2 has 110V/220V PSU or just 110V?
Solution 1:
This US Apple Store webpage says that the current Apple TV (2) has:
Power: Built-in 6-watt universal power supply
So yes, it looks like it will be fine in Europe.
Solution 2:
Yes, according to Apple TV on Apple Online Store description page, the power is a Built-in 6-watt universal power supply.
But another important thing needs to check is to see if the power plug matches the socket in your country.
Solution 3:
I bought it and I confirm that the US version works fine with european 220V/50hz (fine print on the box says also 110V/220V compatibility)