Having a magnet in your pocket along with your wallet, keys, etc. would be annoying anyways.
I get your point, but I was actually thinking of the metal money clip on my wallet. It was more the annoyance of having things stick to your phone, like a loose paperclip in your pocket or something.In mythbuster they found out that it takes 1000 gaus to demagnetise a credit card. I wouldn't worry too much about a magsafe connector.
Most people will probably charge the phone on the computer. Plus, I think an iPhone can survive a fall from a desk.
Dropping a phone from a desk is not nearly as bad as dropping a MBP...