By Lenn Thompson, Executive Editor The Long Island wine community often overflows with more of the same — vineyard walks, mediocre music acts, tenuous food/chocolate pairing events, and the like. These activities clearly attract customers — wineries wouldn't spend the time and money on them if they didn't — and it's easy to simply stick with what works. But two of the North Fork's top producers — Roanoke Vineyards and Shinn Estate Vineyards — are about to up the ante significantly by offering their customers new and unique tasting experiences that are anything but the wine country norm. It's great…