Not sure if this has been suggested before but my suggestion would be once you hit a 99 in a certain skill, you can reset it back to 1 and start over (obviously as this is how prestige works). Now the only thing I'm struggling to think of is what sort of reward you could get from pretesting your skills.
Once prestige'd the XP should be lowered for the skill you're trying to get back up to 99.
Think this would benefit many players seeing as its not really that long to max.
Thoughts/ideas?