I am currently evaluating Dojo, YUI and jQuery. One thing I notice with Dojo that doesn't sit that well with me is the use of custom HTML attributes. Using custom attributes causes problems with validation.
Instead of using dojoType="dijit.layout.AccordionContainer" what is wrong with attaching via CSS class or ID in the javascript. Eg. dojo.setType(document.getElementById('accord'), 'dijit.layout.AccordionContainer');
