Lockpicking, as it is, isn't exactly something worthy of an entire perk tree, and I'm not sure how they could really flesh it out compared to other skills. I'd much rather just see more alternatives to opening locked doors that don't involve a lockpicking skill. I mean, how many lockpicking perks are worth the perks it takes to reach them?
Maybe even Pickpocket should be absorbed back into the Sneak skill. There would still be pickpocket relevant perks, of course (who doesn't love literally stealing the shirt off of a guard's back?), but it would all be dependent on the Sneak skill.
This is of course assuming they get replaced with more worthwhile skills, like Acrobatics+Athletics, or Unarmed.