There are a few issues that can affect when and where a particular game is released.
One of the biggest would be language, since if they released games from Japan in the West without translating them, it would be confusing and annoying, and vice versa for Western games to Japan. I also noted a few European gamers frustrated by delayed release dates. Firstly, most of the games are translated in America, which is why they get the games first, and second because, to the best of my knowledge, they only need to translate it into English and possibly Latin American for America (please correct me if I am wrong about this), whereas in Europe you speak many languages in the different countries, and need to have several of these languages to allow the largest amount of people to enjoy these games.
Second, there are some games that, while they may seem interesting to you, may not be profitable to release outside the native culture, because it doesn't appeal to most gamers in other regions, or doesn't make much sense. For example, the Japanese market gets excited over RPGs and such, whereas many many Western players prefer a good FPS. (I realise I am making gross generalisations here, please don't reply with 'I live here and I prefer this genre')
The last point I want to make here is classification. Living in Aus with no R18+ rating, some games are delayed trying to get through classification, or banned outright. The different rating systems and standards used around the world are another reason you may have to wait for, or not get to play, some games.
All that said though, I think the best way around it would be to do away with region locking, so that if people want to play a game not released in their country, or import an early copy from the US, they actually can, and look to the internet for help if they get "lost in translation".
BTW, sorry bout the length of this post, but I think these are important points to keep in mind.
