Prior art is not dead, but does need to be public to be useful.
This should be a wake up call to the small inventor to file for patent before you show anyone else - with the up side of giving additional protection to everyone when you want VC to commercialise.
It should also be a wakeup call to any corporation relying on secrecy for R&D or complex formulas, if info is leaked (or some leaves a prototype in a pub), either it enters the public domain via the internet or traditional publication and is un-patentable, or someone else files for it instead of you.
e.g if the "secret" formula for Coke gets leaked, someone else could potentially patent and "own" it. If the publish on the web then no-one, not even Coke could patent the formula.
There isn't really an argument, so maybe this is more a lawyer unemployment bill - it's a start anyway.