That wiki entry is wrong and or out of date. It only considers strictly classical irreversible computation. It doesn't mention quantum and reversible computation.

But as to the larger question - yes I think there are probably eventual limits, but even this can not yet be said for certain until we have a complete unified theory of physics: quantum gravity and what not.

From what we do understand of current physics, the limits of computation take us down to singularities, regions of space time similar to the big bang: black holes, wormholes, etc type objects, which are not fully understood in current physics.

Also, the larger trend towards greater complexity is not really dependent on computational growth per se. At the higher level of abstraction, the computational resources of the earth haven't changed much since it's formation. All of the complexity increase since then has been various forms of reorganization of matter/energy patterns. Increasing computational density is just one form of complexity increasing transformation. Complexity can continue to increase at many other levels of organization (software, mental, knowledge, organizational, meta, etc)

So the more important general question is this: is there an absolute final limit to the future complexity of the earth system? And if we reach that, what happens next?