It looks like there’s more and more freedom, Nintendo has stolen.
Well, not really Nintendo, but Camelot is the big problem in this matter.

During our test play, we wanted to test out Online.
We first played with a friend (EU copy vs JP copy).
I didn’t show up on his EU copy, as well as he didn’t show up on my JP copy.
More to note, you can’t join your friend through the Friend List, even though he/she is playing online.
This means, that Mario Tennis Open is Region Locked.

To sum up even more problems, even when trying to connect to Random people, it’s connecting forever, meaning that Mario Tennis Open is also IP Address Locked.
We were even waiting for 20 minutes long to connect, but nothing, nothing at all!
IP Address Locked means, that if you have an European Version of this game, you go on vacation to the USA, try to connect, but it will always fail, because your IP Address is not European.
So, if you want to play online during your holidays, make sure you’re going to an European, Russian, Turkish, South-African, or Australian destination.
Otherwise, you’re fucked.

Review is expected to be released, this Monday.
Don’t have your fingers crossed on a good mark, this pretty much fucked it up already.