The PlayBook is seeing very good rates of OS upgrades, with 96% of all users currently running the newest version of the OS. As a developer this is a good trend to see because it implies that less work will need to go towards supporting older versions of the operating system. (For example the 3% of users still running OS 1.0.3 do not have access to in-app purchases).
In the past this has been an issue for RIM. As of just this past month 12.7% of BlackBerry smartphone users were still on OS 4.6 which was released over three years ago now. Historically RIM has had even more trouble getting users to upgrade existing devices. However, by removing the wireless carriers from the process, and including an simpler, and easier way to upgrade on the PlayBook, RIM does not seem to be having these problems anymore.