Motorola Warns Over Leaked Droid X Froyo Update
WARNING: Do NOT load the leaked 2.2 upgrade that has been floating around on the Internets. There is currently no upgrade path from that load to the official 2.2 load that will be released by early September. This could make it more difficult to upgrade to the official version. Please consider this if you're thinking about loading it.Those who remember a similar issue with the Evo will recall that HTC had to push a fix to the device so that it could get the correct Froyo update. In this case, Motorola makes it sound that you may not be able to update, at all.
It's just something to remember; there's really no "good" reason to rush a leaked ROM build onto your device. You could end up in a bad situation.