This is basically the equivalent of elo hell in the new ranked system.
By putting this "win 2/3 games" requirement, players are required to bet that 2 out of 3 times they'll get a half-decent team with no noobs, trolls, or feeders.
I lost two games due to both times bot and mid feeding (you know, double kills before the minions even spawn?) and I won one where there were two afk's on the enemy team.

And here's the thing: I can't exactly carry my team 1 to 5, as some people would recommend. I tried doing that in a custom vs bots when I was fed 60/0. It still failed, because I got out-DPSed by the enemy team and instakilled.
Meaning, no matter how good I play, if I don't get a good team, it kind of makes the whole system useless.
And if someone crappy gets a good team, their rank just shoots right up.

There needs to be some way that determines individual performance and can award points/ division series wins based on that, rather than solely considering wins and losses. Just my two cents.

Step 1. Play a bunch of games.
Step 2. Identify fellow skilled player who is pleasant to be around and consistently near your skill level and doesn't dick around.
Step 3. Duo queue
Step 4. Win series.

Statistically speaking, there are 9 other players in game. Assuming you are not the problem, this means you have a chance to have a maximum number of 4 bumbling idiots to carry, the other team has a maximum of 5. You are at the advantage in solo queue assuming you actually are as good as you think you are. Adding another person to your team increases your chances of winning even more.

Be social. You have a friends list for a reason. The system works as intended as soon as you realize that you can't continuously win games. You will hit a threshold where players are better than you. Just the same, you will hit a point where everyone around you is so incompetent that you can actually carry 4 idiots. The more games you play, the more accurate your placement will be. You can't play for your teammates, and you can't always have the better team, but you can always focus on improving your personal skills to influence the game more heavily.

Winning lane doesn't win you the game. When you realize that, you're on the right track to improving.

http://dl.dropbox.com/u/41727372/king.jpg ;-;

Both posts seem about right.
Another thing to remember is that now that we're grouped into leagues and other subcategories, it'll be likely you'll be put in a match with the same person quite a bit. After a few matches, take note of who have been in your matches for a while and the champ they like to play.
If you have a hunch that beastly fizz player is on the other side, then ban fizz. If that beastly fizz player is on your side, then ban champs that can make him inefficient in lane and fights.

lol you're just unlucky. I've won all my series so far :P

sample bias.

do enough 2/3's and eventually you'll get a set of two teams where people aren't braindead.

Your first set (or two, or three, etc) is not a large enough number of games to truly call it "elo hell mark 2"

I started in Silver IV and worked my way to Silver ! without any trouble (usually losses were trolls - lost no 2/3s). The 3/5 is kind of a pain though. Its just a lot of effort to go through the cycle. I kind of understand because you can't get a demote.

not good enough. I've done plenty of carrying through trolls and etc in the two series games so far. One more win and I'm gold