If you go with an apple laptop, you would have to go with a Macbook Pro. Macbooks only use shared VRAM. Also, if you do go that route, definitely wait until July. They're supposed to be updated. Trust me on this.
As for a PC, I would go with one of Dell's higher end laptops. You can definitely get a laptop that will play DoD just fine. You might not be able to max out all the settings, but it will work well enough. IBM's are no good - used for business computing. Sony's are cost far too much for the horsepower. Hp's are decent, but...I've never really had good experience with them. They seem to be hit or miss.
So, you can definitely get a laptop to play, but you'll have to find a laptop with enough video power. Look for something with ATLEAST 128 of VRAM (non shared). Good luck!