Nope. There isn't enough convention center space on WDW property to hold an event even just half the size of D23 Expo. The Anaheim Convention Center is booked by Disney for D23 Expos through 2014. The next one is in August, 2011 in Anaheim.
There is a smaller Destination D concept that kicks off this summer at Disneyland; a 2 day conference at the Disneyland Hotel that covers all things related to Disneyland.
They could do one of those smaller Destination D things at WDW, but they haven't said anything about it yet.