Being a HTC model, I would guess it is doable as there are already beta versions cooked for the Touch Pro. The question is can the hardware support it? The Mogul is LOW on memory as is - my first instinct would be avoid an even heavier OS.
XDA forums already has a beta working on the 6800 27 mb's free after load and fairly stable. At least that is what some people are posting. As usual your mileage may vary.
I agree with you jerryyyyy, I am reluctant to upgrade to 6.5.
So this begs the question - Why would I want to upgrade? What features/improvements does 6.5 have over 6.1?
There is some Hex thing from the start menu, which I'm not sure I care about. All the apps I use are easily accessible from cLaunch which I hacked to look sort of like an iPhone.
I don't think I'll be upgrading my Verizon XV-6800 to 6.5 either since it's pretty stable now.
The other thing is even when this gets released I'm sure Verizon will turn it into a slug by installing all the VZW bloatware (kind of like the way the VZW Touch Pro is now out of the box if the test device I played with is any indication).
This includes links to the MR1 and MR2 upgrades and also the fix for the keyboard issues. My suggestion would be to not go this route tho. I would head over to XDA and find yourself a nice custom rom - try this one:
From what I understand, Sprint will probably not release a sprint 6.5 version. ( I dunno about Verizon) Leaving just a custom xda style rom as a choice for the 6800. As for the 27 mbs free after the 6.5 install. That's actually quite nice. Seeing as I routinely after a reboot see my phone at only 18 mb's then with some use drop to like 13 or 14. The Mogul got totally screwed on the memory front. Sadly I am stuck with it until probably after the touch pro 2 era.