I can only relate to the experiences I've has with some other re-exams that I have been invovlved with...all of them took 18-24 months to complete. That doesn't mean these will take that long even though the PTO is very over-burdened right now; and if they have this on a fast timeline for diposition if could help speed the process by 6 mos or so. The thing to watch for is the number of non-final actions that are posted. The examiner will communicate back to the patent holder with his concerns via this method and it usually takes 3 mos. or so to get a final disposition on each of the examiners actions...letter writing back and forth etc etc. The less there are of these the quicker the final outcome.

Also things to remember are when an ex parte re-exam is in progress it allows the holder to also 'tweak" the patent claims to further strengthen the patent and  usually, if the patent holder is successful in keeping his claims basically intact, the final action posting by the PTO gives the patent an even stronger base to deal from.

Claims can be changed and/or eliminated but as long as the claims that are the heart of the patent remain intact the patent ends up being strong enough that any future attempt to invalidate them or challenge them by a potential infringer is useless.

Obviously what we and the comapny want now is a quick resolution with the patent coming out of re-exam as strong or stronger than before.

JMHO