Well, players will still be able to switch to whatever server they want to play on... they'll just be logged in through either the EU or NA datacenter.
Well, I guess we'll have to see for ourselves (once the game is released, as they are still very much working on performance atm) how server switching to a server from different region will impact the amount of lag you perceive. And I guess the same applies to people from Australia/NZ, Asia, Africa, South America, etc... only after release will we really know how playable the game really is from those regions.
About ping issue, it is true that in some ways, I find it hard to enjoy an MMORPG where I have a ping of 250 ms at all times. Ping is the time it takes for a computer to send data until it receives a response from the server destination. No matter how well the server performance of Anet, they will only affect NA players or those that are in NA or EU vicinity.
If US players connect to the NA server and initially play at 10 ms, where Anet made an improvement of 3ms in their server. Then their ping would become 7 ms, which is a significant 30% increase in response speed. Now, that 3ms improvement is experienced the same way for other people, regardless of location because that's the amount of time to process data received until they are sent back to the source.
Now, if we took at another example of a player connecting from Malaysia to NA server, where they initially get 250 ms of ping. That 3 ms ping server performance at NA server is a constant, and in the end Malaysian player get 247 ms of ping, which is hardly significant (1.2% increase as opposed to 30% increase of US players)
These examples will mean that no matter how well their server is configured to maximise performance, Ping time will always depend on location and how far the computer is communicating with the server.
MMORPGs are supposed to be worldwide, and even though we can access NA server, it is unfair for the players living on the other side of the globe to have the unfair disadvantage of those living in the western worlds. A real true fact of MMO gamers are that, The number of Asian+African+Australian+Oceanean players who are interested in playing this game outnumbers the amount of players in NA or EU.
What it would be nice is to have a server based somewhere in Singapore/Malaysia where every player around Asia and Australiua can play Guild Wars 2 without ridiculously high ping.
If the game sells enough copies in Asia and Australia/NZ, then I'm sure ArenaNet will consider it. Fact is that the vast majority of copies sold of GW1 were sold in North America and Europe, so I can understand ANet's decision to start there with their GW2 server park.
Im sure it will end up like Star Wars The Old Republic because they didnt have an Oceanic servers, but then realised their were alot of Australians and New Zealand's buying the game and now they have oceanic servers in SWTOR.
If I am living in Canada and purchased the EU version, is it allowed ? Apart from support and possibly lag issues, I can login and play GW2 right ?