Yet one conclusion that I draw from his work is that on a warming Earth there should be more attention directed to other methane sources, which are quicker to degas than [ocean] clathrates. In that respect, I find reports of degassing marshes and bogs in Siberia releasing their CH4 of far greater concern.

I have seen/found very little continuation of the science I then wrote about. 2007 was marked with a methane increase in CH4 atmospheric concentrations - experts were hesitant to relate this to increasing thaw of permafrost. In fact, it seems to be unclear what caused the increase in 2007. There's also this:

Renewed growth of atmospheric methane

Following almost a decade with little change in global atmospheric methane mole fraction, we present measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) networks that show renewed growth starting near the beginning of 2007. Remarkably, a similar growth rate is found at all monitoring locations from this time until the latest measurements. We use these data, along with an inverse method applied to a simple model of atmospheric chemistry and transport, to investigate the possible drivers of the rise. Specifically, the relative roles of an increase in emission rate or a decrease in concentration of the hydroxyl radical, the largest methane sink, are examined. We conclude that: 1) if the annual mean hydroxyl radical concentration did not change, a substantial increase in emissions was required simultaneously in both hemispheres between 2006 and 2007; 2) if a small drop in the hydroxyl radical concentration occurred, consistent with AGAGE methyl chloroform measurements, the emission increase is more strongly biased to the Northern Hemisphere.

I haven't found numbers of atmospheric CH4 for past year; I suspect they will be released soon.