I've been wondering about this system for some time now, and after mulling it over and realizing some things, it's clear to me that the coolness system in its current state doesn't come close to doing the job it intends to do. So, just to get it out there, I'm going to go through just why this is.
Intent
First of all, let's get out of the way what the coolness system is supposed to be. At its core, it's supposed to be a mechanic rewarding those who do good work in the judging stage by giving their entry more exposure. Which is a good idea, but figuring out who has actually done good work isn't necessarily easy to do, and right now it's not being done particularly well. Most people would like to have their game featured high on the list, so for most people participating in the judging, gaining coolness is quite desirable. Right now it seems like a lot of your coolness is based on receiving hearts, and therein lie most of the issues of the current system.
Issue One
The first and foremost issue is this: It seems like the hearts you get from comments on blog posts count towards your coolness. This is a grave, grave problem, as the comments you leave on blog posts have absolutely nothing to do with whether you've been leaving good feedback on games or not.
Not only that, but there are stickied blog posts by means of the news section. Those posts will remain at the top of the site for several days at worst, meaning anyone who leaves a good comment in one of those will get a ridiculously higher amount of hearts from there than they ever would from giving good feedback to a game. Clearly, blog post hearts need to not count towards your coolness.
Issue Two
If you want to gain hearts, people need to see your feedback. If they can't see your feedback, you won't get any hearts. This ultimately means that if you want coolness, you have absolutely no reason to ever give feedback to a game that doesn't already have a lot of attention. It's one thing for people with coolness to get more exposure, but for people with little coolness to be essentially actively shied away from is taking it too far. This means that the longer a game remains in an attention rut, the less feedback it's likely to get.
Given that we're all in this for fun and games, I think that the system should at least put some effort into giving attention to those in sore need of it. You shouldn't have to feel like you need to competitively critique games in order to be noticed, but right now, that's pretty much how the system works.
Issue Three
If you want to gain hearts, people need to like your feedback. A lot of games don't get much attention, and most people probably don't take the time to both play a game, critique it, and read the other critiques. This means that most of the hearts a comment will get will be from the creator(s) of the entry you're critiquing, which further means that sucking up to the creator(s) is often the dominant strategy. People might be withholding constructive feedback because they're afraid the creator(s) won't like harsh feedback and thus not give them a heart.
For a lot of people, an event such as this offers immense potential for growth. Getting that one comment that tells you something you really didn't want to hear, but probably needed to hear, could be the difference between being stuck in a state of being happy with being less than you could be and actually growing your skills. So having a system that encourages people to suck up takes away a lot of the value of this event.
Issue Four
For some of the more deviously competitive participants out there, this isn't just an issue of having a lot of coolness, it's an issue of having more coolness than everybody else. This means that the meta game here is to make sure you personally gain as many hearts as possible while everybody else gain as few as possible. This can lead to some pretty nasty tactics.
For example, people could try to arrange brigades by making people blindly give hearts to their own comments, while blindly withholding hearts from other peoples comments. This suddenly means that the hearts do not reflect whether they actually left a lot of good feedback or not. Additionally, what reason would a person wanting to top everyone in coolness have to ever give other people hearts? That way they're only strengthening their opponents, and they get nothing back for it.
Conclusion
Given all these issues, it's become clear to me that the coolness system just can't stay as it is. Primarily because it's broken, but also because it's inherently going against the spirit of Ludum Dare. Coolness is supposed to be a reward you get because you're sincerely doing your best to give people valuable feedback, but right now it's more like an exposure boost to whoever says the things people want to hear in the places they're most likely to see it. It pretty much does the opposite of what it's supposed to do, which is to encourage people to leave good, constructive feedback.
P.S. Not trying to hate on Mike here, by the way. I think he's done great work to make the site work this time around. I'm sure he has his hands full, and he's doing this for free too, so I think maybe he needs to be cut some slack. I just really think the current version of the coolness system needs to be changed ASAP.