The current knowledgable buzz is that Disney wants to intentionally keep Carsland as an attraction unique to DCA. Why?
First, that investment singlehandedly brought attendance at DCA back up to profitable levels and Disney doesn't want to cannibalize that by replicating the attraction elsewhere. Or put another way, the thinking is keeping Cars just at DCA helps make the
Disneyland Resort complex more of a unique long distance travel destination (unlike WDW, a large proportion of the traffic at DLR are locals; Disney has been working ever since WDW opened to try and get more long distance travelers back to DLR).
Second, the orginal second element of the knowledgable buzz was that Disney would complement the "unique" cars element by putting a unique Star Wars land in HS in Florida.
However, that thinking changed when Disney formally announced they were planning on putting Star Wars attractions in Tommowowland at Disneyland. The rumour was Star Wars would still also be added to HS in Florida, but the latest word is due to belt tightening, the Star Wars additions in CA are on hold and the ones for Orlando have been cancelled.