For the Monk, I can't think of anything that would help, other than being replaced by the Swordsage.
Tsk, tsk.
I, for one, love monks as is, but I understand that some don't.
There are some things that could help attract other players to the class.
1) AU/AE has a feat called Hands as Weapons, which allows you to enchant your unarmed strikes as if they were weapons- not unlike the Kensai (CW PrCl) class ability.
Its not a huge step to incorporate that feat, and further expand upon that concept and have a HR feat called Body as Armor, or allow them to wear light armor without penalty.
Caveat- if you let them wear light armor, limit it to true light armor, not heavier armors made with special materials.
2) Use one of the myriad Monk substitutes out there (like the OA version which adds weapons and removes the multiclassing bar, or the Rokugan Inkyo), or possibly lift some abilities from those other classes to incorporate/substitute for extant abilities (and make no mistake, some of those other abilities are quite nice). If you're adventurous and industrious, you could make a more flexible "Ur-monk" class that includes some or all of those variants' abilities as part of a menu of options.
See this thread for more details: http://www.enworld.org/showthread.php?t=221182&page=1
3) Gestalt it with a similarly "underpowered" or less common class, like Soulknife, Soulborn or Binder