Pros & cons of a single OS partition

My fellow administrators and I are going to vote on a standard for partitioning hard drives on our company?s servers. We are going to compile a list of pros and cons for having one large partition that includes the OS MS-Win2000. Or two partitions, one partition for the OS and one partition for the data. In the past, when partitions were limited in size by MS-WinNT, we always created two partitions, one partition for the OS and one or more partitions for the data. This isn’t the case since the publishing of Win2000. What is your opinion on the pros and cons of one single large partition?