adobe photoshop - Do I need to create my images at twice the pixel dimensions on a retina display?

I just got a new Macbook Pro with Retina and I'm confused about how to attack my PSD's.

If I'm designing a site which has 14px font size, should I be creating it at 28px in Photoshop to see what it will look like in CSS on a standard display?

Or if my website should have a 60px tall header, should I make it 120px in Photoshop?

I guess I'm confused because the CSS stays the same, but I'm wondering if I should be doubling up on everything in Photoshop to get what it would look like in CSS on a non-retina display?