As Dave says, there are a whole bunch of people selling heavy tools and frameworks and calling them "Agile" where they are anything but. Safety, to pick the obvious example, is not an Agile value, and numerous commentators have called SAFe nothing but RUP in Agile clothing.
Declaring Agile dead seems a bit naff, but obviously the manifesto lacks values and principles to address Dave and Richard's concerns.
So I've kicked off an initiative to do exactly that. Agile: The Next Generation or A:TNG for short, augments but does not replace the Manifesto values with four new ones specific to Agile at scale. It offers pattern languages (not frameworks or methodologies) based on Kurosawa's The Seven Samurai" and the thousand year Iroquois Confederacy.
Most importantly it rebases the whole Agile Alliance shtick on github, where it can be properly open and we can properly self-organise and evolve it without some clique of middle aged white guys dictating to the community at conferences.
Details and some starter patterns are up at http://agiletng.org .
So, yes, Agile is dead. And long live Agile! -- Peter Merel.