Disney has not officially announced any removal or replacement at the Streets of America.
Rumors have been flying about lands based on Cars or Star Wars somewhere within DHS, but, so far, it's business-as-usual at the park.
Even if one (or both) of these rumors eventually turn out be true, it would surprise me if construction begins before 2015 or 2016.
Disney is now finishing the Fantasyland expansion at the Magic Kingdom. In 2014, Disney will begin construction the Avatar-themed land at Animal Kingdom, which was announced in 2011.