I ran a poll here on the site a couple of weeks ago to find out which versions of Exchange Server people were currently running. Even though some people had trouble answering because they manage multiple environments there were still 182 people who responded to the poll.
The results are interesting to see.
Exchange Server 2010, which RTM'ed in November 2009, comes in at 50% of the market according to the responses received.
Exchange Server 2007 was lagging in 3rd place early in the poll but overtook Exchange 2003 to reach 26% of the vote. I actually thought this would be lower by now because the move from 2007 to 2010 is not as complex as migrating from Exchange 2003 to 2010.
But as I think on it more it probably makes sense. After all I was still helping customers migrate to Exchange Server 2007 at least six months after Exchange 2010 was released, and continue to work with Exchange Server 2007 customers today.
Exchange Server 2003 came in third place which makes a lot of sense, although the 20% share of the vote was definitely a surprise for me. I expected there to be some element of “skip every second version” out there in the market but if those customers have been waiting for Exchange Server 2010 it has been out long enough now to have done something about migrating. For those who haven't perhaps there are good reasons such as application compatibility or just the sheer scale of their environment that is slowing them down for now.
I almost didn't include Exchange 2000 in the poll. Luckily I did and it received a handful of votes. I'm genuinely concerned about those customers since not only are they running an unsupported version of Exchange but they are also presumably running it on an unsupported version of Windows (2000). And unless they've converted those servers to VM's they are also very likely running on out of warranty hardware.
So what about you, why haven't you upgraded your Exchange Servers yet?