Could you try and differentiate the mashups from traditional portlets?

First, I should point out that Mashups can be published as a JSR-168 compliant porlet. But more importantly, Mashups can be published BY THE USER as a portlet, as a spreadsheet, to a mobile phone, etc. Traditional portlets are crafted by portlet expert (i.e. programmers) and don't give the creator the same broad set of destinations.