Interestingly it seems as the Soundlink Mini II just appeared in some European Bose-stores so far and can be ordered from there immediately,
The new model looks just like the old one, but it is available in black or white now. It gained some new features like speakerphone that was missing on the original model, voice prompts (probably the same as on the Soundlink Colour), it can finally be charged through MicroUSB and battery life seems to have been slightly improved, but no other obvious changes so far. I am not sure if the new one will really sound much different, there is not a single word about changes in sound etc.
To tell the truth I was expecting something completely new, more rugged maybe, water proof or whatever, but it seems as if Bose just tries to sell the same speaker again only with some new added features that were simply lacking from the original.
As soon as I can get my hands on a unit, I will check out if the sonic qualities have indeed improved over the old Soundlink Mini, if not the Soundlink Mini II will have to fight against some strong competition with the JBL Charge 2+, Denon Envaya Mini or the upcoming RIVA S.