Believe it or not, I had the same dilemma a little while back.
I was looking to either buy the Mini or the PS3.
Or actually, I was looking for a solution watch my backups on my telly.
I decided to get the PS3 because it also plays PS3 games (duh), because it has blu-ray and because it was cheaper. In the end, I just wish I'd gotten the Mini because getting backups to play on my PS3 is such a damn hassle and I can't even watch blu-ray on my tv!!
Get the mini! It looks awesome and sleek and it'll do anything you want it to do.