Optimality of Zero Capital Taxation The Chamley-Judd result of zero optimal capital taxation says that 0 capital taxation are required in order to maximize welfare at the steady state. 

The result is 30 years old. Still assuming that we only care about the steady state, what's the literature's take on that? How esoteric is it? Or in other words, are there simple extensions of the model that completely overcome the result?
There is quite a bit of work being done in that area. One very recent example is Straub and Werning's working paper "Positive Long Run Capital Taxation: Chamley-Juff Revisited." 
The point seems to be that we need to consider the rate of convergence to the steady state.

Also, there is other literature that gives some competing results (e.g., "the new dynamic public finance" literature). For a more complete summary of mainstream objections, see Diamond and Saez, "The Case for a Progressive Tax: From Basic Research to Policy Recommendations," (JEP, 2011). They devote a whole section to why they think the Chamley-Judd result is not policy relevant.