There is no effect of the Part 3 Wetlab on your NYS license.
I took the Part 3 in June 2009 and it was easy as hell. The Part 3 consists of 2 sections (one each day). The first day is the written portion which consists on pharmacy calculations, look alike-sound alike (you write the indication) and errors and omissions. The second day is the compounding lab where you have 3 hours to make 3 products (mine was a solution, an ointment and obviously an IV) each one was ridiculously easy to do if you have had good practice in compounding in a lab setting. (January 2010 was a ointment, suspension and an IV). With each item there are different points assigned to the characterisitics to making the product (such as salicylic acid in an ointment needs to be mixed with only a plastic spatula since the acid is corrosive to the metal spatula - so if you used a metal spatula you got a couple of points off).
The catch with NY is the Part 3 is only offered twice a year (January and June) so if you fail it then you have to wait 6 months to try again. Most pharmacy schools in NY offer review classes with wetlab practice (probably too late now) they are usually in late December and early May.
All in all, if you have had good practice at school with lab products then you will be fine. "Study up ... its a bitch" doesn't come close to the exam, it's too much common sense and not difficult at all.
Hope that helps.