In an announcement that has snuck on to the official Linden blog, Linden Lab has announced that anyone running a bank in Second Life will have to produce "proof of an applicable government registration statement or financial institution charter" or have their content removed starting in two weeks time. This follows the collapse of Ginko, which we covered in exhaustive detail, and complaints that several other banks have defaulted on their 'promises' and are still advertising unsustainably high interest rates (which is, of course, part of their attraction too).
The wording affects anyone offering interest payments, which means, I believe it will also affect WSE's practises - they offer a low rate of interest on saved money, although a normal stock exchange business would still permissible since dividends aren't interest as I understand the law.
It will be interesting to see if any of the banks survive this transition, and if they don't, what comes along in their place. It will also be interesting to see if there is a run on the banks now.