Makes sense to me, handing over the jet services to National Jet/Cobham. The contract is signed until 2017 (?) I believe, so why not use that resource rather than paying Alliance for charters? That, as JetA points out, frees up aircraft for the money making mining routes.
It's all a result of short staffing though, mostly from poor management decisions.
Also, I agree that the Sunnies 'Jet Clause' has nothing to do with it. It was a vain attempt at a dangling carrot from the last EBA.
With regards to improving services to counter the ATRs introduction, I think the recent move back to Max Cruise on the Q400 fleet might have something to do with that... Who would've thought - when you fly faster you get there quicker!