No...the "official" updates and even custom ROMs are very specific to the device...
something for the Milestone won't even work on the original Droid (or visa versa) and those two phones are almost identical....
I've only seen one custom ROM that has been designed for the Droid Pro, but last I saw it was still a work in progress and somewhat buggy....unfortunately the Pro has not and probably will not be a phone that developers get involved with...I'd love to try out some of the ROMs that I used to use on my Droid....would really improve things...
i do miss my old droid but, i think i got a really good phone its just dum that when you look up one theres one better; look at the first droid a milestone to all.