You Will Be Able To Update Pleo's Personality

By the looks of it you'll be able to reprogramme your Pleo. I'm not sure when this will come about, but there's talk from Ugobe that this is on the top of their priority list. The sort of customisations you'll be able to do is to create new moves (like the Christmas one), sounds etc.

Over time they'll allow you to tinker how Pleo reacts to his "status" such as hunger, sleepy, playful etc. I'm not too sure when this will happen either.