Legal Effect Of Patents On User Interface Elements?

cmickelson asks: "Adobe has filed a suit against Macromedia for infringement of Adobe's patent on 'tabbed palettes.' Details available here. What does the Slashdot community think of this? I'm especially concerned with the possible effects of UI patents as it relates to open source software. Is it possible that an open source project could be sued for violation of some company's obscure patent on UI elements? Are developers concerned about this? Should companies even be able to patent something as nebulous as a user interface?" Patenting a "look-and-feel" is about as trite as patenting an idea. Who cares that your UI "looks like" somebody else's. If UI "a" performs better than UI "b", well isn't that what competition is all about?