What's the optimal size screen for a tablet? Short answer: who the h-e-double hockey sticks knows. The tablet is so new, it's too new for things like screen size to be ubiquitous. 

Having sold more than four million units since coming out last spring, Apple is the closest thing to an industry standard at 10 inches (9.7 to be exact). Interestingly enough however, the rest of the industry seems to be ignoring that rule of thumb. The tablets now coming out (or soon to be coming out) are typically seven inches (Samsung's Galaxy Tab, Research in Motion's Blackberry Playbook, to name a couple).

With the iPad experiencing such success with a 10 inch screen, I have to wonder why the other guys are putting their chips on seven inch screens.

Earlier this week, Apple CEO Steve Jobs weighed in on screen size at his company's fourth quarter earnings call. Jobs put to rest rumors that Apple is working on a seven inch iPad. It's not happening. Jobs says the software looks better on a 10 inch screen and he's not compromising.

Will he live to regret that (or change his mind)?

It will be interesting to see what size consumers will gravitate towards once they have a choice.

Feel free to follow me @oricchio