Since several people have been complaining about the lack of removable batteries on the new uMBP's(to be honest, I don't personally know anyone that actually carries spare batteries for their laptop). In any case, for the few people that actually do need to carry extra power on the road, why not just create a custom back plate which can easily be swapped for the factory one? The back plate would be identical but with one little upgrade - a sliding removable battery cover (such as the ones on the back of remotes/cell phones/etc.) Apple couldn't make batteries removable because the latch-release mechanism takes up too much space. This, on the other hand, is basically just the original plate but with a door cut out to access the battery. You would unscrew your original back plate, put in the custom one, and that's it. You now have the best of both worlds! A high-capacity battery that's still removable/easily accessible on-the-go. Check out my mockup and let me know what you think.