OS 4.3.1 betas show Wireless Upgrade as an Advanced Option for the 8700, so I'm assuming it will be extremely compressed.
As for the automatic activation, that is part of the process for OTASL.
Also, there should be no restriction for downloading SP5 and applying it to BES Express. There may not be a full installation available for BES Express, but the service pack should have no issues with installing over your current installation. I could be wrong, but I can't think of any possibilities for limitation with that. The beta of SP5 updated my installation with very little issues (I did have to move the database from MSDE to SQL2000 to do the database upgrade, but I think that was limited to my environment (and possibly a bug in the installer) rather than the actual update). I have since moved my test BES to Enterprise, but I still anticipate the same issues. The installer crashed when trying to update a database trigger. This particular trigger is not upgraded when on MSDE, but I think it was exposed and present due to some previous testing/migration between MSDE and SQL for documentation purposes.
Just throwing that out there.
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