Dualboot with Boot Manager on Galaxy Nexus I own a Samsung Galaxy Nexus (GSM/maguro), running AOKP with ROM Manager and ClockworkMod Touch Recovery installed. I want to try MIUI using Init2Winit's Boot Manager application and with the same data and settings as my AOKP install. Since the Galaxy Nexus only has a single internal memory partition, I'm afraid Boot Manager will not work properly because, as the documentation said, it is based on loading another ROM from external memory.

Now I can install MIUI to the 2nd slot in Boot Manager and have the option to wipe System, Data and Cache, but what will be wiped? Is it possible to use Boot Manager on the Galaxy Nexus?
I've used Bootmanager on my Nexus S without issue and I believe that you will be able to wipe the system, data and cache of your second slot without it affecting the original rom.  

But this will be easy for you to test:

Make a nandroid backup of your phone.  Always make a nandroid backup!
Once this is done you can go crazy and try installing MIUI but make sure you install gapps too (or the miui equivilent - sorry I'm woefully inexperienced with MIUI but I'd imagine they also didn't distr the google apps with the rom) - (the last time I installed a ROM using rom manager I needed to hunt out a different version of gapps than the ones that come with CM or AOKP - something to do with these version being scripted as opposed to just flat APKs).  You need to install gapps as you'll need to have the market to install bootmanager again in order to change roms.  There is a way of doing this manually through the shell and fastbook, but it's not fun.

If anything messes up then restore your nandroid backup and you are back to where you started.

Have fun :)