Another issue that just popped up after the Winter '12 upgrade is that I noticed that the apex:outputLink element, when there is no text between the opening and closing tags, will by default render the value of the 'value' attribute (i.e. the URL being referenced) as visible text in the HTML anchor tag.

So this code:

<apex:outputLink value="http://forcearchitects.deliveredinnovation.com" title="Force Architects: Cloud Computing and Salesforce Architecture Blog by Delivered Innovation" target="_blank" styleClass="menu_blog" rel="nofollow" />

Renders this HTML:

<a class="menu_blog" target="_blank" title="Force Architects: Cloud Computing and Salesforce Architecture Blog by Delivered Innovation" rel="nofollow" href="http://forcearchitects.deliveredinnovation.com">http://forcearchitects.deliveredinnovation.com</a>

While this code:

<apex:outputLinkvalue="http://forcearchitects.deliveredinnovation.com" title="Force Architects: Cloud Computing and Salesforce Architecture Blog by Delivered Innovation" target="_blank" styleClass="menu_blog" rel="nofollow"> _ </apex:outputLink>

Renders this HTML:

<a class="rssLinkSprite" target="_blank" title="Subscribe to Delivered Innovation with RSS" rel="nofollow" href="http://feeds2.feedburner.com/forcearchitects"> _</a>

The behavior prior to the Winter '12 upgrade was to simply render an empty anchor (the hyperlink is on the container element).  Now it inserts the full URL as text in the anchor tag.  Is this the new expected behavior of the element?  I don't see any documentation spelling this out.