Did RealClimate have a post on this? Not that it matters; I would be interested in how someone could draw meaningful conclusions about solar activity based upon the inferred climate of Pluto.
but the point of showing warming on other planets is to simply to show that warming is not anthropogenic.
Just because other planets have climate variability (which one would think they might) doesn't prove or disprove an anthropogenic influence on climate here on Earth. The only thing I would deem relevant is a clear linkage between solar activity and climate change on other planets. As I've posted previously (just above is the most recent time) solar activity does not explain the current warming trend on Earth. That does not (in any sense) indicate that variability of solar activity is not an important climate influence. It certainly has been and would be expected to be.
but other than that, there's not much science at that site that I can agree with.
If there was only one side to a given issue, debates on that issue would be short and boring.
global warming on Triton
global warming on Enceladus
(In case you don't have enough planetary warming links). I agree that warming or cooling on other planets doesn't negate any hypothesis on earth, but it does show that other factors are at work (geological, solar, etc) that can produce quick effects. Solar activity is too complicated to rule out. The luminosity is easy to measure (and shows tiny decreases), but the effect of increases in the sun's magnetic field are not well understood.
The RC site does not have balanced debates by any measure. Several skeptics were kicked off for being rude (they were rude, no doubt about it). Thin-skinned debators are not good ones, that's why it's so nice to have you here!