Feature: Two New SEO Features

We’ve added some rewrite engine rules so all default page variations redirect to the main domain name.  In other words, variations such as “/store/” and “/store/default.aspx” and “/default.aspx” all now redirect to the root “yourdomain.com”.  This keeps the page rank juice on the 1 url (instead of multiple)and removes duplicate content issues. 
Note: Due to feature differences between IIS versions, this only works on IIS7/Windows 2008 servers where most new installs go.  Some old installs are still on IIS6 but are steadily being migrated to IIS7 servers.

and secondly…

301 redirects from https:// to http:// url conversions, instead of 302 redirecting them.
There was a relatively rare case that triggered a 302(temporary) redirect instead of a 301 on some sites. 301 redirecting allows us to tell engines to permanently send the traffic to the new url and should allow the old url to be dropped from the search engine indexes over time.