EB3 is expecting to be the first EB category to exhaust its annual immigrant visa quota number, we expect sometime in 2005, we will see EB3 facing the non-current priority date again. Based on late 1990 experience, it could be over 1 year wait.
So keep your NIW, or if possible, go for EB2 LC.
But if you can afford to wait (stable job security), EB3 LC is also OK.