I think this depends on the definition of the word "roaming" as Bill Clinton would say. Since the 521 does not support WDS, you will roam, but not very quickly. Roaming is actually a function of the client and if the autonomous APs are configured the same then when you meet the client devices' roaming threshold you will move to the next AP with the same SSID. Does this mean you wouldn't have to reassociate and reauthenticate? NO. You WILL have to do both of those and it won't be fast. So, if you're deploying a latency based application like voice or video then you will have slow roams and jitter or dropped calls and video streams. WDS was created to compete with Airespace and like minded companies that used PKC or credentials caching to speed roam times up to less than 10 milliseconds(same subnet, same controller). One of the main reasons that Cisco acquired Airespace was this ability to run latency based applications much better than their existing autonomous solution. SO, as Bill Clinton said, "I can not roam with that AP, the 521!" when in essence, he just did!But, oh so slowly.
