Robry is a highly respected individual in the Nat Gas community. His compiled data on storage is very accurate. Check his blog, there is a lot of useful information. From the data he tracks, he is looking at increasing demand from industrial users. These users are key to resolving the oversupply that we are facing in the nat gas sector.
I certainly don't doubt robrys data, and would love to see a huge increase in NG pricing as I derive a significant chunk of my income from NG, but...
...the resource plays that are available (haynesville alone could make up undersupply for a while to come), and the number of idle rigs now suggest that any marked appreciation in NG pricing due to supply/demand will quickly be met with the drill bit.
But with this stock who cares about glut or supply. I think the point of the original post would be higher demand equals higher volume for etp. No brainer, if ETP is hanging in there in this economy, then it stands to reason that the slightest uptick in the economy will have a positive effect on demand, and thereby increase volume.