It's unlikely—very, very unlikely—that there will be a bigger iPhone anytime soon. At least, not with Tim Cook at the helm.

When the Apple CEO was asked on Wednesday, straight up, if Apple plans on launching a larger-screened smartphone, Cook said the size of the iPhone 5 is just fine.

"Without sacrificing the one-handed ease of use, we've put a lot of thought in screen size, and we believe we've picked the right one," Cook said.

Of course, Steve Jobs felt the 9.7-inch iPad was in the Goldilocks zone, and now there's an iPad mini. Should we believe Cook that the current 4-inch screen is the "right one?" Probably. At least until Apple releases an bigger iPhone.