The adwords tool lets you see global and local searches for the territories you specify - does that answer your question?
About ranking on .com vs .no ....well, there's a bunch of things to consider there. A basic step is geotargeting - check out http://www.seomoz.org/q/google-webmaster-tools-international-seo-geo-targeting-site-with-worldwide-rankings you can set in GWT which countries your site is aimed at.
For a more comprehensive discussion look at http://www.seomoz.org/blog/international-seo-where-to-host-and-how-to-target-whiteboard-friday
