Sorry for getting to this so late. I have been busy putting out other fires.
Here is a summary of all the questions and answers:
Bday:
Exchange 2007 RTM RU6 will not install onto of Exchange 2007 SP1. It is blocked and you will get a generic MSI error that means that this MSP (update) Is intended for another product (RTM) and not (SP1)
Installing Exchange 2007 SP1 Rollup 1 onto of Exchange 2007 RTM will also result in the same error. It is just blocked at the beginning of the install at the MSP logic level. Nothing really happens at this stage.
FYI - Installing Exchange 2007 SP1 effectively uninstalls the Exchange 2007 RTM MSI, and any rollups installed, and then installs the SP1 MSI. You can see this by looking at the Exchange setup logs during SP1 installation for the upgrade scenario. You will see the msiexec /uninstall action for the RTM MSI before the SP1 MSI is installed.
SP1 Rollups will be marching out about once every 8 weeks or about then. RTM Rollups stand a chance of becoming less frequent. The majority of fixes will be going into SP1 rollups and less frequently into the RTM code base.
I am putting the above info, as well as other information, in another blog posting that will be out soon. Please keep your questions happening and I will make sure that I answer them in the blog.
Mr. Crowley:
Yes this is an interesting comment about exploiting issues between products. I will pass this on.
OllyM
You should continue moving to SP1. Since RU6 isn't a security release, it seems that you could quickly review the fixes and see if any of those apply to you.
The latest rollup will always be available on the download center and Microsoft Update (MU)/WSUS/WSUS<->SMS. MU will also do the detection for you and offer the correct rollup. The downside with the MU method of deliver is that a Cluster OS will not be offered any Exchange 2007 Rollups. You must go to the download center and deploy these either manually or with a SMS-like system. This is an entirely separate topic that I haven’t written about yet and probably should.
I hope that I answered most everything. If not, add a comment.
Scott Roberts (Exchange)