Having (or better, limiting yourself to) a single vendor is not standardization at all, in my opinion.
I'm not talking about having a single vendor in a single company at a certain point in time - that's good, doing differently is hard to manage (since usually the sysadmin team is really too small).
I'm talking about having all the sysadmin jobs in my area using Linux as a synonym for Red Hat Linux.
I hope that's not the only standardization we will get, since I don't really like vendor lock-ins (talking about Windows...) and I think we need something better than that.