I just did some quick calcuations....
The area the CDRom disk takes up:
16136 pixels^2 (it's an image, so you can extrapolate its relative size)
And the are the battery takes up
18018 pixels^2
So if we get rid of this thing, we *could* potentially see 10 hour battery lives on Macbooks. TEN HOURS!?! Not only that, you have an entire side for external inputs, 2x USB 3.0, 1x Firewire 400, an Express Card slot WITH a memory read on the other side. Lets add in HDMI for the heck of it as well since there is simply just so much room on each side.
Or maybe not a new battery (5 hours is enough), how about a new cooler? Something that'll make MacBook Pros actually laptops compared to every other laptop out there?
Imagine if you will a laptop at full load at no more than 50-60C or idling at 35-40C? My GPU currently with a *slightly* bigger cooler went from 80-90C full load to 45-50C. That is ridiculously different than what it was before, and the cooler is still incredibly quiet and isn't that much bigger. The size increase from the default cooler vs the Zalman cooler's size change isn't as great, maybe 1.5x larger. If you open your macbook, you'll notice that only a small bit of copper at the very top near the screen, maybe 30cm x 5 cm long piece of copper is doing all the cooling. Now imagine they have a heatsink the size of your DVD ROM. Weight wise it is still very light (if they use aluminum, my alu Xigmatek cooler is ridiculously light compared to the size)
There are simply so many things that can be put into the space of the DVD ROM right now. Off the top of my head, a magnetometer, a GPS, a 3G, essentially a phone. Imagine if you laptop had a wireless card that you stick a SIM card into and it turns into a phone that ALWAYS has internet (albiet slow) when out of wifi.
Now that's a crazy laptop.