No, the resorts don't all have buses that go to the other resorts. What you can do (if you don't want to drive yourself or take a taxi) is to take a bus to the nearest park (for AKL go to AK, for GF, Poly, WL, FW or CR go to MK for Y&BC or BI you can go to MGM or Epcot) and then take the Disney transportation to the resort you want (you may take the bus or in some cases the boats).
We have also done the DD bus, but it was the longest bus ride of our life! Now, that doesn't mean we wouldn't do it, just that it was not our favorite means!