I was just wondering that because I am using it myself. Although there is a disclaimer on the line where the link is, I still wanted to try it (even though it's potentially dangerous since it's in the Beta stage).
Extra Comment after I posted this:
>_< Crap, I should have posted this in the CCleaner Discussion...
Yeah I have it installed. It hasn't done anything it shouldn't so far.
Considering that it still depends on the same .ini file as the old CCleaner it should be relatively safe(but still its a beta so use at your own risk.)