In Diablo 3, you can play ANY region you want, but you can't move your character with you for any cost. Your friends list from WoW or SC2 will be available in D3, but ONLY in the region you play SC2 or WoW.
For instance, if you play WoW or SC2 in Europe, then your friends list will be available in the Europe realm of D3. If you choose to play the Americas realm in D3, then you will have to create a NEW friends list, because your WoW/SC2 friends list will ONLY be available to you in the Europe realm. The same rule goes if you play the US/North America realm in SC2 or WoW and want to play a different realm in D3.
More info regarding your character/gametag and such is here
http://us.battle.net/support/en/article/diablo-iii-global-play-faqIt will be pretty cool to be able to play with anyone, anywhere, in the game. Some of you have my hotmail email addy. I will mostly be playing in the Americas realm, though I might play Europe or Asia from time to time.
