A solid argument exists for having a real banking system in online games.  Even Goliaths like WoW have a “Bank” which is essentially no more than a safety-deposit box.

You can read the whole entry at EyesLikeOurs, but I would like to make a further point.  In addition to adding value directly to the players by establishing a true banking system,  There are economical manipulations one could do to control the rampant inflation that plagues MMOGs due to the cursed face of Gold Farmers.  Certainly it’s not a quick fix, but it could help in management.  I believe the concept of providing loans would also be useful in resolving the issue (As many will prefer to go into debt to get cash now, rather than give their very real currency to Gold Farmers).