FOR decades, Silicon Valley has been the land of eternal optimism and high anxiety, traits that pitch into overdrive anytime a seismic business event washes across the corporate and entrepreneurial landscape here — like, for example, Microsoft’s blockbuster $45 billion bid for Yahoo on Friday. . . . http://www.nytimes.com/2008/02/03/technology/03yahoo.html?_r=1&oref=slogin