It certainly does. I had to replace my credit cards already for a fourth time not knowing the reason for it, until I realized it was the magnet of the iPad cover.
Not only it has destroyed all of my credit cards, but also it has ruined my Kindle screen (and I am not sure if it can be fixed or have to replace the screen....)
This is the "only" problem I had with my iPad, and I will not give it up just fot that. I guess I will have to buy a shielded wallet for all my credit cards!