The Atlanta Journal-Constitution had this article over the weekend on the Dale Chihuly lawsuit mentioned here on several occasions. It correctly sums up the "philosophical and now legal issue [as], where does one draw the line between an object done 'in the manner of' and a knock-off?" It also quotes one of the defendant's lawyers as saying (1) "you can't claim a style" (not entirely true; see here) and (2) "the [object in question] has to be virtually identical before there's any infringement" (but that doesn't seem right either; in general the test for infringement is "substantial similarity").
Meanwhile, Bill Patry went to check things out for himself, at the Bronx Botanical Gardens. His verdicts: (1) "The show was fantastic"; and (2) "On the copyright side of things, I saw works that were complex and creative as well as works that were not much different than you would see at Home Depot. But even for the highly creative works, the scope of protection would seem narrow, limited to that particular expression, and certainly not extending to style or technique" (emphasis added).