Few suggestions:
1)Busy - Currently we have a way to set busy, which prevents everyone from messaging you in game. I think this should be adjusted, or at least expanded upon -- Myself, and most other 100s I know, set busy solely for the purpose of keeping noobs from spamming them for power leveling, free RBs, etc. I think Busy should prevent anyone who is more than 5 levels lower than you from being able to message you, while still allowing anyone your level range or higher to communicate with you. This simple change would drastically reduce the spam from little nooblets.

2)Friend Invites - Currently our only options for friend invites is "everyone, or only friends" - I think there should be a third option added "only people in my level range". This change would allow people to readily accept invites from friends, as well as other random dungeon runners their own level, while preventing noobs from spamming you with group invites (Which I might add is EXTREMELY DAMN ANNOYING, when a noob invites you 10 times in a row, never sends you a message, never asks to party, just throws random invites to everyone higher level than them hoping someone will accept and help them /rant)

3)Trading - Currently with trading, people can open a trade with you at basically any time unless you have specifically added them to your ignore list. It gets extremely annoying having noobs open random trade windows all the time and then saying "free", or opening trade windows and popping in some rbs and begging you to trade them. I think the trade system should be changed so that you can only initiate a trade with someone your level, or lower. As it stands, if 2 people agree to make a trade, it is not difficult for the higher level to open the trade request. This would prevent all the random trade crap that is getting worse and worse (this easily happens at least 5-10 times a day).

4)Chat Channels - Please God, PLEASE add a new chat channel for level 75+. There is so much crap that gets spammed non stop in noob, world, and market channels. I find myself frequently /leaving each of the channels just to ignore all the crap being spammed so I can talk with my group, friends, etc. A level 75+ chat channel would filter out most of the junk for those that have reached the higher levels.

I personally feel these 4 changes would drastically increase my satisfaction with the game, as well as the satisfaction of many other players. The changes would go a LONG way towards retaining the existing player base -- as many of us who reach 100 not only get bored (which we can deal with), but extremely annoyed by all the junk I've listed above (Its the junk that causes a majority of us to move on).

Sean

Variations on all of these ideas have been posted on idearunners.com. Go vote for them.

Or unless you are set to Busy