Actually, and with apologies to Hamlet, Jeff Stai of Twisted Oak Winery says that *isn't* actually the question.
The main issue for a winery isn't, "to blog or not to blog;" but whether or not to develop the changes necessary to keep your Website alive and interesting. Either you make the investment, or your Website is effectively a stagnant brochure.
Absolutely. Well said. Hear, hear. You get the idea... Our research for The Winery Web Site Report shows that the number one failing of winery Web sites is freshness, and a well-kept blog is an easy antidote to that problem.