Lucent's patent battle against Microsoft goes back several years and began in 2003 when Lucent sued Dell and Gateway. In that suit, Lucent alleged that the included Microsoft operating system infringed on several video compression related patents, including patent 5,227,878. Dell and Gateway argued that they were merely resellers of the software and - because of prior indemnity agreements - asked Microsoft to step in.
Microsoft has yet to respond to the new suit. This could turn ugly, so keep tuned for more details.