I think one of the reason why mintpal or poloniex are not adding cloak on their exchange is because of the exchange anon function. This has never been done before and to their perspective, it is a big unknown. Maybe the devs are talking to them and explaining how the anon exchange function works, maybe they're waiting for this function to be tested and proven. who knows whats going on behind the scene?
I don't expect any big exchange to add cloak until the anon exchange function has been successfully implemented and tested.
They added dark and xc, both of those claim first anon coin but are yet to produce working anon function. Cloak actually could become the first truly working anon coin which is a HUGE thing. Testing starts very soon (today and tomorrow)
Drk or Xc is supposed to be decentralized anon. yeah they haven't yet successfully implemented anon function and their price now is purely on hype and market manipulation. If cloak successfully achieves anon exchange function in couple of days, we're gonna see huge increase in value.
so far the dev have been very professional when it comes to announcements and releases. when they say they're gonna release something, they're on time with it. so I feel pretty good about the anon exchange being implemented on Friday.