I agree with @monkeywork, i think Microsoft is now in better than what it was in 2003/4, At the time when i worked there we knew Linux was a challenge, MSSQL, AD, Exhcange all had still competition(sun one Ldap, domino mail/workflow) and was fighting hard in fact i would say Domino with it's workflow was in better position. With Azure, SQL Always on, .net and solid Windows server i expect Microsoft to be around for long atleast another 1o to 12 years in dominant position in enterprise segment.