What to expect....
•Unavailability of BES related services (mail redirection, PIM data synchronization) during migration and device initialization process
•Expected delay of 2hrs-3hrs before complete resumption of services. Some devices may complete the initialization process quicker than others, and may be able to send/receive mail. Time may be much less..all depends on the number of users.
•Some devices may experience prolonged initialization activity due to limited device resources, user mailbox size or quantity of PIM data to be synchronized
Appearance of the enterprise activation icon during the initialization process...goes away when process is completed.
There should be no problems with the devices you mentioned. The 7290s together with the 4.0 BES server will now be able to participate in wireless activations or enterprise activations. Which means no need for the DTM to synchronize.