Google on dynamic vs. static URLs

First, a quick explanation of dynamic and static URLs.

A static url looks like mypage.html or pricing.php.  No question marks, no ampersands (usually).  Pretty much nothing after the file extension.

Dynamic urls look like index.php?op=1&val=dlkjs&id=234skjdf.  Normally these are used on sites that pull their page data from either databases or data files on the server. 

The theory has been that search engines like static urls better because they're easier to make sense of and tend not to have duplicate URLs pointing to the same content.  So many dynamic sites rewrite their dynamic URLs to look like static ones.  A lot of blogs do this.  This forum does too.

Well it looks like Google is now recommending against rewriting dynamic URLs. 

I'm not sure that it's worth redoing sites that are already using a dynamic to static rewriting method, but next time I start up a site I will probably leave the URLs dynamic and not worry about rewriting. 

Although, as I'm typing this a couple points for another side came in to my head. 

There are theories out there that static pages tend to get better click through rates from search engine results because the user can more easily make sense of the URL. 

I've also seen it recommended that you try to keep whatever technology you're using for your site out of the URLs.  So instead of having mysite/pricing.php it would be mysite/pricing/ .  The thinking is that it's a lot easier to redo a site in another language down the road if the indexed URLs aren't language specific.  I've gone down that road before and it does take a little work to make the switch work.  One of my earliest sites was written in classic ASP so all the pages ended with .asp.  I rewrote it in PHP and has to do a lot of redirecting from .asp to .php to keep search engine traffic happy.