I believe the argument for right sided navigation (at least) is that it gets all those generic keywords for navigation over to the right and more page specific keywords further up the page. On the flip side, I gather that this "prob" can be overrun by using divs or absolute positioning???
Ideally I'd say a 2 column layout should be marked up in this order:
Header (logo and headline)
Main section navigation
Section specific navigation
About the company profile/about us:
I agree: I blundered, I meant to mean company profile should go under about us.
I like about us, I don't think it too 'folksy', rather, I think it adds a nice 'human touch' to a site.