The whole concept of a card that holds your keys does not actually make sense.
What do you need a card for? And hardware beyond your control that reads it?

You already carry everything you need along with you all the time.
It's called a cellphone.
Install a wallet app, load some change onto it, and you're set.

Making merchants accept payments via mobile phone is already happening, not even affiliated with Bitcoin, it's called "mobile payments" and is considered one of the most important markets of the near future, so we don't even need dedicated Bitcoin merchant terminals. All we need is mobile payment solution providers to also prepare for Bitcoin. And they will, because Bitcoin is just the hype of the day when it comes to talking with venture capital.