Meredith Angwin of Yes Vermont Yankee made a keen observation that over the last year, the number of new natural gas exploratory wells is collapsing. Why is this happening? Namely because of the cratering current price of natural gas.
In fact, a very interesting thing appears to be happening right now with shale / unconventional natural gas recovery boom - the industry appears to be a victim of its own success. Or rather, drillers have been sinking new wells without regard to price (again, see the sharp boom in new wells up until about October 2008, where new wells peaked). As a result, proven reserves have fairly substantially increased - and in particular, known reserves of "dry gas" (i.e., nearly pure methane, the most commercially valuable component of natural gas) have in fact "exploded" - nearly doubling over the last decade.
Meanwhile, neglected in these considerations is that shale fracturing wells in particular aren't cheap to drill; as a result, anomalously low natural gas prices means that some drillers have been losing their shirts over the same much-publicized "boom" in natural gas production.
This is where we get back to the discussion of natural gas prices overall. What appears to be occurring is a basic disequilibrium; a disruptive event in supply (i.e., introduction of large new resources) prompted a rush to invest/explore this resource, which in turn created a significant rise in supply over the short term, rapidly dropping the price to a point where the market price is below the profitable price of recovery.
Thus, as far as exploration goes, we seem to be observing is basic mineral economics: exploration follows price. When price drops (i.e., we had an over-abundance of exploration), exploration drops. As prices rise to the point where new wells achieve a net profit, it's a relatively safe prediction that exploration will again begin to rise. What is essence is developing are two constraints on natural gas price - a "floor" on prices (i.e., below which it is not economically viable to recover gas from new wells) and a "ceiling" (driven by the large increases in known supply). My colleague Alan observed this some time ago when he speculated as to whether we are seeing the end of natural gas price volatility (at least for now).
So, will natural gas prices rise? Probably - but given the very large amounts of known reserves, price acts as a strong signal to start drilling again. Given the large known new reserves, this will inherently push back against any significant rises in price - as it gets more profitable to drill new wells, new producers will inevitably get into the game, particularly because we know the gas is out there. The real question is, "At what price does this happen?" I'm not an expert in gas recovery, so I don't know - but like Meredith, I suspect it will be around $5-6/MMBtu. A columnist at Forbes suggests it may be $8/MMBtu. Either way, I remain deeply suspicious at this point of the idea of prices "exploding" (and hence my bet with Rod) - what instead appears to be happening is the search for a new price equilibrium.
A final addendum - as commenter Robert pointed out, all of this really applies to the U.S. - something worth emphasizing. Other places, where either fossil resources like coal and natural gas are less abundant (i.e., South Korea and Japan) or where there these resources are more valuable as exports (i.e., UAE) have a completely different picture for the relative economics of nuclear versus natural gas. In particular, it is likely far easier to make the economic case for nuclear in these places - meaning even if new builds for nuclear may be slowed or delayed in the U.S. for the time being, the same is not true abroad.