Yes, well we already have translations. The thing is to set this up in such a way that the site is displayed in one of the three scandinavian languages depending on wether the site is visited on its .no .se or .dk domain. The language is really not the problem, showing the right one of the three available is the thing.
As I see it, there are several possibilities. We could install the site in three different localized versions on each of those domains, and let the three installations use the same database. Not sure if that would work well, because having all the content available to each of the sites would mean they all need to use the same table prefixes.
Or we could use a single installation, and determine the language of the browser or operating system, and give the visitor a localized version based on this. The problem with this is that many people in Scandinavia prefer the English version of both operating systems and browsers, so they would get the site in English instead of Norwegian, Swedish or Danish.
If it's possible, we could have a single installation still, and maybe determine the language to be shown on wether the site is visited on its .no .se or .dk domain, but as these all are forwarded to the same installation this would be somewhat tricky and may not work in some browser configurations. The reason for this would be that browsers with high or custom security settings would warn the blogger about being forwarded, and could either jump to the main .com domain where the actual installation is, or cause some other problem that would gum up the work... and the user experience.
There may be several other workable solutions, though the first alternative I mentioned here seems to be the best one so far, if it is possible. If there are people with experience setting up such a site, please chime in. :)