I was just playing a solo normal game (none of my usual team were on) and was rocking with Mordekaiser.
We lost the game. Held out forever (72 minutes) but still lost.
After the game, I decided to look at who I was matched with and against. My team consisted of me (310 wins), and 4 other people who averaged 140 wins.
The opposing team had an average of 490 wins and only had 1 person beneath the 400 mark at a mere 392 wins.
Is it just me or is something ****ed with the matchmaking?

Well, seeing as you didn't see their losses, you have no clue to even estimate their ELO. Your teammates could have been 150 wins and 2 losses for all you know, and the opponents could have been 400 wins and 500 losses.

# of wins != skill. It equals time played.

A 72 minute match? Sounds like a good game, why are you complaining?