(Oh god, this turned into the OT from hell. Apologies to OP. Maybe I should take all this and make it into its own thread? Nah. Maybe later.)
Reading these posts, I've been thinking about ways for us, the competitive players, to come up with such a system ourselves (at least for the time being), and I think I have a workable idea. I'm going to lay it out as it comes to me, so bear with me if it's not perfectly organized:
There would be a webpage where you register with your Stardock account (and here's my first question already: you can't attach your serial to multiple accounts, can you?). Then each time you win a game on ICO against someone else who is also registered on this webpage, you'd submit a win for yourself with the accompanying replay. The losing player would be sent a message asking him to confirm the result. If there is no activity from the losing player within 7 days, the win is automatically confirmed.
(I know you want to scream at me already, pointing out all the things that are wrong with this, but please bear with me for another moment as I go through the rest of the features)
The replay the winning player has to send would be kept on site for about 7 days (or until a certain quota of diskspace usage is reached) (after which the replay's checksum could be archived forever to check if the player tries to upload the same replay twice) in case an admin wants to check the legitimacy of the win (or that any game happened at all).
If the designated loser responds that he did NOT lose that game (or that the game never happened), we are in conflict. The designated winner can either say "oops, my bad" and the entry is simply removed, OR there can be an unresolved conflict, in which case the game data is dumped too, but each player has the other player's nick entered into their "blacklist", meaning that they can no longer report wins against that player (unless both parties agree to mutually revoke the blacklist status). This simply means "oh oh, this player does not play fair, don't play games with him/her anymore". (Hah! Her! As if!

)
The page would then create a ladder of players. Winning against a player of much higher standing than your own would win you a lot of status points, while winning to someone much lower than you would give you much less.
Now there are a million ways to game this system and either cheat your way up or simply break the system and make it no fun for anyone in it. Obviously. What I'm hoping, though, is that someone who seeks out an additional webpage to add that competitive aspect to their game experience is serious about playing this game and thus wouldn't waste time on ruining it for everyone else. Essentially I'm hoping for a sort of wikipedia effect where there will be much more people interested in making the system work than there would be interested in breaking it.
There are many more things that get in the way of this system:
1) It requires activity on the player's side. You need to look up your enemy, find out if he's registered, then log a win, upload the replay (remember to keep the replay as well) etc. This will discourage people from actually doing it.
--> yes, but in the absence of another system for ranking this amount of activity might still be acceptable for hardcore players
2) Replays can be HUGE. Uploading them will take forever, eat up tons of bandwidth, bankrupt the owner of the server, etc.
--> well, not really. Replays can be compressed rather well; up to 90% reduction in size are entirely possible. This brings even a large replay down to less than one megabyte, and many high def pictures are that size. On the server side, bandwidth is really not that expensive anymore these days. Unless we'll have 100,000 active users on that site (yeah right) I don't think this will be a problem on the server side.
3) Logging that win and uploading that replay will take a lot of time! I want to spend my time playing, not registering the outcome of my game!
--> and you will be spending most of your time playing. What's 10 minutes of uploading a replay compared to 4 hours of playing?
4) People will break and abuse this system.
--> yes they will. As Dave Gahan reminds us, people are people. Still I think that with a semi-decent statistics module, it will be easy to spot those trying to game the system, and then we can simply ban their account from it. Since I understand that you can't just create a new account and attach your serial to it whenever you want to, that should be a simple and effective measure. Also, like I said earlier, I think those people will be a minority.
5) Well, you can talk the talk. But do you expect coders and server admins to fall from the sky?
--> no, I don't. But I think I could walk the walk. I have set up database driven webpages like this from scratch before, and I have about four years experience working with a CMS. I also have a server that should be able to take the load, up to a point. I don't foresee this becoming a HUGE success anyway, so I think my server should be able to handle a few dozen submissions a day. However, there are two things I'd like to know before dedicating the time and effort to making this happen:
a) do people like the idea? Is there sufficient demand for something like this?

what are Ironclad's plans for the immediate future? I read that frogboy said SOMETHING like this would be added somewhere "down the line". In the other post we spoke of tournaments. Did he mean a ladder by that or actual one-time, register and be there at the right time tournament like things? Because the latter wouldn't get us anywhere, I think.
So if Ironclad are going to add a workable ladder-like thingie to ICO soon, I can just put this idea away, but if it doesn't look like that will happen and if there's enough demand for this, I'd sit down and hack something out. I'm not a great coder by any measure, so I'll definitely solicit help from any volunteer.