According to the Nokia site, the N810 WiMax version is only available in the US.
If you can wait, I'd wait for the N810 WiMax version to come out. If you live in a large city that is going to have WiMax, you'll probably want that version. If you don't want WiMax, I suspect you'll be able to pick up a regular N810 for less money than you can today because people will be selling their regular versions used because they want the new version. Just my 2 cents.