Hi, No Halfyank. I didn't see the Discovery Channel show, but yes, the entireYellowstone district is one very vast volcanic caldera, (in fact I think it is rated as one of the biggest calderas in the world today) that was active at one time in the distant past. And yes, eventually this area most likely will go up again in the distant future. In fact, I've heard that there are certain sections of this region that are growing ever so slightly each and every year. But as long as it continues to be able to 'breathe' so to speak, it should basically be pretty much okay, as far as you and I are concerned. Of course if it gets plugged up............ well then, all bets are off.
Most definitely though, if the Yellowstone region would go up it would put us into another Ice Age at the very least, what with very vast amount of dust and ash it would put into the air, not to mention the ash and unbelievable volume of pyroclasitc flows which would be put directly on the ground throughout the whole middle western area of the US, clear to the Mississippi River Valley.
Whether this would be as big as the Lake Togo eruption, which I've heard it said actually changed the chemical makeup of the Earth's atmosphere, it would be hard to say, but I'm thinking that even if it wasn't, we, as a species, wouldn't be around to measure the difference between them.
But still, an eruption of the magnitude of the Krakatoa event of 1886, or the Tambora eruption of the early 1800s ( when the world experienced a "summer without warmth,") and both of these events generated in the same immdiate neighborhood as the geological hapenings going on today, would most definitly change the history of the human race as we know it, what with all the nations of the world so totally interlocked, fiancially speaking, on one another as they are today.
If one of these two volcanoes, or one of the other over 100 volcanoes in this region decides to go truly magmatic from these latest underseas quakes, the current power structure of the world as we know it today would at the very least be changed. For the better or not, is not for me to say, but be changed? Most definitely.
We may be living in some very interesting times to come. Or Not. Mother Earth can be very fickle about these things, at least to human understanding.
Take care, Sgirty