The formula really isn't all that complex, it should be reasonably easy to reverse engineer if you care to. If math is good, then actually do some :P.
The basic format for the formula is something like:
power = Current HPD + HPD investment in hardware + (cost of improvement for highest version of every file typed owned) * some modifier + some reasonably small virus modifier.
I don't think power matters all that much, but if you still haven't figured it out in an hour I'll have some data that should at very least let you aproximate it...
As for this gold anonymity thing... What are you talking about? I've never really had any issues determining who has gold (though I have had issues determining who a given gold owner really is), but I'm fairly certain having gold only has peripheral effects on power (i.e. they can keep their files off their actual servers and lower power, and of course, gain power faster).
I agree on the reverse engineering part, with time it can be determined, (I may actually make a second account to try and reverse engineer it) but as it stands now there is no general consensus as to what actually affects power rating. I was under the impression that the only thing that affected power was the software you owned, not the HPD you have or how big your server is. I've been upgrading my hardware much, much more than my software, and my power rating hasn't moved anywhere. Also, I think it takes into account everything on your Gold FTP as well, so backing things up doesn't allow you to drop your power rating.
So as I see it power = sum(highest version of each software type * modifier). I may even suggest completely reworking the power calculation (as others have suggested) before actually releasing it.
As for gold anonymity, it was mentioned in another thread that with IP change and the ability to change your server's name and description, you couldn't tell if a server you came across was someone you've never met or a hated enemy, unless you take detailed descriptions of their hardware/software profile, and even then you'd need to find your target again quickly before too much of it changes. Being able to calculate power just by what files are present would help match a server with a username.
Oh, there's also a poll up there, for those who don't have anything significant to say.