I have made "creative" use of the new html5 elements, sometimes pushing the intended boundaries a bit.
Like most, my site is mainly made of articles comments and links to other articles. I decided that I'd use the article tag just once, so there's no confusion whatsoever. For comments, I'm using the aside element and I think that it fits the definition - it's related to the content but it can be done without.
In the case of links to other articles (actually, titles with excerpts and taxonomy aids), I've decided to just use the nav, for lack of a better element, and I know that this is where it becomes tricky. Normally, nav is intended as a list of links for the main navigation. Well, clicking on related posts actually is the primary means of navigation on my site (and most web 2.0 sites). They're also a "list" of links, as beside the main link they also contain a link to the category listing, one to the author's other posts and one to the date-based archive.
The issue is that there are 10+ such navs on each page (can't wrap them in the same nav as they're not all consecutive), which was probably not intended by spec authors - or was it?
The code validates just fine and sectioning makes sense as well, but I wonder if there still are any practical consequences to this. I don't want the site to be a nuissance to screen reader users, for example (otoh, if it's no nuissance, I wouldn't want to cater for a problem that doesn't exist either). So what is the worst that could happen?