then Germans will pull out off EU reinstating mark and forth reich
Who told you the plan?!?!? It was supposed to stay secret until the big moment. You ruined the surprise.
a) Poland is not a big enough country to play the currency game against the big world banks. If JP Morgan want to make another announcement predicting a drop in the zloty strength (like they did two years ago) just so that they can make a killing on the recovery, the national reserves are not strong enough to counter that action. The country simply isn't strong enough (yet) to compete in that sort of market.
The zloty was devalued to stimulate exports and investment during the downturn, which it successfully did by expanding the money supply and dropping rates.
b) Poland signed the Maastricht treaty, and must join the Euro at some point; it's simply a matter of when. As other countries around it adopt the Euro, there will be increasing political pressure on Poland to join the bloc, with Germany and France's own banks stepping in to mess the zloty up until Poland has no choice.
Well...kind of. They are bound to join the euro, but there is no time frame. NBP isn't stupid, hopefully they'll hold onto to the Zloty as long as possible.