No, this does not help. I use MediaWiki for my homepage and I want to use the same URL as OpenID. So I added the following to the head of my template:
<link rel="openid.server" href="https://secure.example.com/openid" /> <link rel="openid.delegate" href="https://secure.example.com/openid" />
Actually it works, I can sign on with www.example.com (e.g. to Wiki Commons) but my (OpenID)user gets converted to www.example.com/index.php/Main_Page
Don't use the example.com/Page_title URL scheme. It isn't supported by developers and WILL break in ways you can't foresee (and if it doesn't, the developers might break it in a future version just to spite you). Some examples can be found at http://www.mediawiki.org/wiki/Manual:Wiki_in_site_root_directory#Reasons_why...
While it's still possible to do this, it's not recommended.