To the surprise of absolutely nobody the release of iOS7 by Apple has resulted in a number of reports of problems with iOS7 devices connecting to Exchange servers.
Exchange MVP Paul Robichaux brings to light an odd iOS 7.0x Exchange ActiveSync problem affecting some, but not all, iOS7 devices.
With the memories of serious iOS6 bugs still fresh it is no surprise that many Exchange admins are proactively blocking the new 7.x versions of iOS while they perform testing or at least wait for reports like the above to emerge.
If you want to go down that road (and I encourage everyone to consider it and make their own risk assessment) then fellow UC Architect (and ActiveSync guru) Dave Stork has written a handy guide to blocking iOS7 in Exchange 2010 and 2013. Dave is collecting a list of DeviceOS values that he has spotted in the wild which will assist with creating the device access rules to block/quarantine the devices.
Also worth keeping an eye on is Michel de Rooij's post that is tracking a few of the non-Exchange related security issues with iOS7 that would justify many organizations blocking it entirely.
All in all it seems little has changed and yet another iOS release means yet another string of bugs and security issues for Exchange admins to deal with.
It sure looks pretty though.