The bitbill patent will prevent others from keeping keys of wallets and trading them on paper. Is there any discussion of this idea prior to May, 2011? The patent covers uses that go beyond paper. They want to shutdown physical bitcoin coins apparently.
Patents don't shut things down, but are weapons to do so.
It is like a gun. You can build one, but that doesn't mean you are going to shoot everyone.
They can be enforced, or not. They can be licensed. If you want to make a similar coin, talk to them. They are likely smart and reasonable folks. If you have something new to add, you might become partners. If you just want to steal their idea+research and make a buck, maybe you should pay them something?
When you tip well, you get good service.
When you don't, you get served.
