I doubt the release dates would be the same. After all, they're still going to be released from different bases (Nintendo of America and Nintendo of Europe respectively), and with the latter, there's more to do as well - translating not only into english but many others as well, organising the releases for them in multiple countries, changing the whole PAL region stuff... plus the different laws that apply would also mean the games will have to differ furthermore (such as the instance where Europe's Platinum had to go without the Game Corner's minigame due to laws there).
Expect Europe to get it after America, is my prediction.