your lucky, for some reason I dont even see the miui rom available in rom manager, I have the desire, tried every thing I can think of but the miui rom is not available in rom manager, and it says your rom provider does not offer ota updates, am I doing something wrong?
I would also love to know the answer to the original post, will it upgrade or wipe, as like many people spent a lot of time setting things up just how we like em ;-)
Phire I assume you mean upgrading the recovery itself to 188.8.131.52. You can upgrade and downgrade the recovery no problems. Although you may want to hold of as many flashable zips have not been upgraded to use the 3.0 recovery.
phire, each time, I install the new version of MIUI using ROM Manager.
You can use it by selecting the "Install ROM from SDCard" (or something like this) option.
ROM Manager will ask you if you want to proceed a backup and/or a full wipe.
No problem with signature or something else.