becoin, the only question you have to ask is "What would a judge think?". The law is not a program. It is not an algorithm you can find security holes in to hack your way through it.
A judge would clearly believe Bitcoins have value, as would any reasonable man after seeing MtGox, so securities laws would apply if you issued shares denominated in BTC. End of story. Even if you strongly disagree with this please don't go on posting because there is really no ambiguity here - your interpretation of the law is wrong and the other posters are correct.
Of course one thing which we've seen happen with Bitcoin businesses is them starting out handling small amounts of other people's funds and eventually handling large amounts.
Yes, this is a problem not just from a legal perspective but also because it's insecure. Over time I'm hoping some of the services such companies provide migrate to P2P networks so the security and legal issues go away. Of course eliminating the centralized marketplace/exchange doesn't mean the participants suddenly become unregulated.
The only solution for that is to put pressure on politicians and regulators to reform the laws so they scale down appropriately. It's easier if you can show a thriving marketplace that's clearly A Good Thing(tm) but is in a legal grey area.