I don't think this has been posted yet, but there is some CSX railroad related work going to happen near the GAP trail near Confluence and the Pinkerton Tunnel area.
CSX runs the operating rail line that parallels the GAP Trail along much of the way. CSX is modernizing this line to accommodate doublestack container cars from the East Coast to Ohio. Primarily, this means ensuring that there is sufficient height along the length of the line. In order to do this, CSX is actually lowering the railbed in some places and while removing overhead obstacles in other places.
One area is the Blue Lick Truss (Keystone Viaduct) near Confluence. This bridge is going to be raised to achieve the required height for the track below. The website listed below indicates that bike trail will be open during the construction, noted to occur in Q3 and Q4 of 2011.
The CSX is "open-cutting" their railroad tunnel that pierces the Pinkerton Neck, meaning they are actually going to remove the overburden and the roof of the tunnel. This is very near, but separate from, the closed Pinkerton Tunnel on the GAP Trail. It appears that this will not impact the Trail itself, but you will find a lot of forest has been clear cut on Pinkerton Neck. According to the GAP Yahoo Groups, the overburden that will be removed by the clear cut will be placed on top of the Pinkerton Neck. I hope that the work doesn't negatively impact the Trail.
For details:
CSX Railroad Work Near GAP Trail