Exchange Server 2007 and Windows Server 2008

I’m in the process of hardware selection for our new Exchange ’07 server. We are finally getting to bring it in-house. We currently have about 75 mailboxes, but are looking to have 100 – 150 within the next year.

My question is, with Windows Server 2008 available now, would you recommend that I take the plunge and go with Windows Server 2008 for my Exchange ’07 Server, or would it be better to go with the tried and true Windows Server ’03?