Featured events to include daily or weekly leader boards
Everyone remembers the forgotten event ;-)

Now try to think of the forgotten event with a few extra added features. First add a daily and a weekly leader board specifically for the event with scaled rewards for the top 1000 players based on number of chests smashed or forgotten bosses defeated. First place would get an incredible award such as a vanity and 1000 plat and 1 million gold. 2nd - 5th place 500 plat 200k gold and a bundle of randomly selected pinks. 6-100 place etc 100-200 etc, 201-500 etc, 501-1000 etc and then 1001-a little gold and a free vanity for taking part.

There would also be a target to hit in say a one week event with a reward every step of the way. So for example kill boss 10,000 times for an elite reward. And rewards each time you hit 100 kills, 1000 kills, 2000 kills, 5000 kills, 7500 kills and so on. The prizes for personal objectives and for leader board weekly and daily standings would range from gold to platinum to exclusive items / vanities.

So the featured events would have:
1). Leader-boards to add competition between players for events with rewards based and scaled on final leaderboards standing
2). Enhanced personal quests with longer life to suit casual and hard core players alike with rewards which get better and better

I've plucked numbers and made up prizes out of thin air. Correct me however you wish to. I'm just suggesting the concept of enhancements to featured events to make PL more active by making it more competitive and exciting with events with amazing rewards for players.