Clone hard disk of old macbook to new macbook? I have a MacBook mid 2014 with Yosemite on it. If I buy a new MacBook, can I clone the disk from the old MacBook to the new one and have it boot up just like if it was the old one?
Yes. 

You will need a thunderbolt cable, boot the new computer in target disk mode, and use something like Carbon Copy Cloner to do the job.

Copying via the recovery partition is also possible, but fiddlier.