If they're sufficiently close (and I admit I have no idea how to calculate Roche's Limit) their upper atmospheres will even mingle. At that point both planets will be visibly egg-shaped and you have yourself a Rocheworld scenario.
--Sam
"I'm taking off the kid gloves, and putting on the very mad gloves."
--Sam
"I'm taking off the kid gloves, and putting on the very mad gloves."