i have known about this version for some time now.here's what i think and it's just my opinion so take it for what it's worth.
first of all,you have to understand the relationship between germany and it's surrounding allies.germany sometimes builds equipment for specific countries with specific specs requested.furthermore,sometimes germany will actually make available certain types of military weapons or mods to advanced equipment to it's allies even before they are available to the german army itself.a prime example of this is the modular systems for the leopard II tanks which ,for example,spain most definitely had even before germany.germany has been doing this since about the 50's.
what does all this mean? not much really but if your going to sit on the fence on buying a p99 expecting some brand new version,you'll probably be sitting there untill the cows come home,lay eggs and pigs come out.
also,this polish version does not constitute any radical change except maybe the sand paper-like texture to the grip which seems like the same as HKs which was competing for the contract and so walther delivered this mod to elliminate any though in the polish goverment considering HK as having something they may want.it worked.
personally i have HK and although giving great grip,at the range,that sand paper like grip gets uncomfortable after about 50 shots or so and would not be happy if walther went for this in the future.there's nothing wrong with the grip they have now.it was designed by a famous italian team that makes designs for the olimpics and also the pioneer of all the modular grips that we now see on every polymer pistol out there...but this is just me.
do i have a chrystal ball? NO,but i dought they'll be changing the current one any time soon.
long live the p99AS!!!...and i do mean AS.