When statements such as "SOA is dead" or "Web 2.0 is dead" are expressed by individuals who are seen as authorities on these subjects - like Anne Thomas Manes at Burton Group on SOA and Richard MacManus at the ReadWriteWeb on Web 2.0 - it is a sign that they have gotten bored talking and writing about the technology or concept in question. As they are clearly some sort of early adopters, this is likely to happen some time before the technology or concept becomes adopted by the masses.
This reminds me of something Clay Shirky wrote in his book "Here Comes Everybody: The Power of Organizing Without Organizations" and which I have previously commented on when referring to the post "Waiting for virtual environments to become boring" by Roland Legrand:
Somewhere in this book Clay says that the transformative potential of a technology on society is realized when that technology becomes boring. Old enough people remember the days when office workers watched fascinated how the first faxes where being transmitted, and later on when the first emails where actually being used in the office, or the first time access was granted to the World Wide Web in the office.
To me, this is when technologies and concepts such as SOA and Web 2.0 become really interesting. We can all start seing how they affect society, business and individuals. I think this is where the discussion should continue.