There was an app called bootpicker that we used with success in Lion, but have since moved away from dual boot machines (We are now using Parallels) before Mountain Lion came out, so I have not tested it with ML. I believe it will accomplish your needs.

Here is a link from Apple that might help.

http://www.apple.com/au/education/resources/bootpicker/

That bootpicker download link appears to be broken. If all else fails, I've uploaded my bootpicker deployment package (created in Composer) to my dropbox at https://www.dropbox.com/s/e694d31p30ijdg9/Bootpicker%20for%20Lion.pkg

It is configured for Windows to be on disk0s3, but that can be changed either by converting the pkg to source in composer or after the fact by deploying another /Library/Preferences/bootpicker.plist

We use rEFIt: http://refit.sourceforge.net/. It's not longer being developed, but it's still working for us. There is a version still being developed called rEFInd (http://www.rodsbooks.com/refind/), but we haven't really investigated it yet.

I can confirm that bootpicker works with 10.8.4 If you are deploying to a number of machines you can package and deploy a customized bootpicker backgroup image along with some configuration settings in /Preferences/bootpicker.plist

I have a script I've whipped up to set the Windows partition in the bootpicker plist based on the name of the windows partition. I also know that TwoCanoes sells a product called BootRunner with similar functionality. They seem to have stuff that "just works" with Casper so that may be worth a look.

rEFInd is the way to go if you want to choose your OS without having to boot Mac OS up.

BootPicker (And I believe BootRunner) run on top of Mac OS.

Are these EFI solutions remotely manageable?

Are these EFI solutions remotely manageable?

Yes, as long as you have the timer set so that the computer boots up automatically at some point. Ours boot Mac OS by default after 20 seconds.

Thanks for all the help!