In my non-professional experience (A.Dip. Network Engineering, many years experience system building, desktop and GIS support), this is perfectly safe. It is a simple change that is easily undone, and you can also backup the registry entry and restore it if it all goes pear-shaped. In fact I recommend making a backup before editing anything to anyone considering fooling around with the registry.
That said, your IT group may take a very dim view of such activity, if not banning it outright - for good reasons usually. It's the equivalent of fiddling around with your car's spark plug cables and fan belts - while the engine is running.
So I'd say that Derek Law has it right, and everyone interested in this tool should vote up the idea. It's quite silly that in this day and age, we're relying on a 10.0 third-party extension and registry hacks to manage enterprise geodatabases!