After Dell and HP, here is yet another concerned Microsoft partner and PC manufacturer: http://www.pcworld.com/article/id,134962-pg,1/article.html
"Acer president Gianfranco Lanci today became the first major PC manufacturer to openly attack Microsoft over the Windows Vista operating system. He was quoted in the Financial Times Deutschland . Lanci said the operating system was riddled with problems and gave users and businesses no reason to buy a new PC, according to the report."
Business 2.0 blog provides more links on this topic: http://blogs.business2.com/smallchange/2007/07/windows-vista-c.html