Has reversing the active runway direction ever led to lined-up aircraft taxiing to the other end of the runway? I was in an aircraft yesterday waiting for its turn in the departure queue on the taxiway and noticed that the windsock was showing a direction approximately 30 degrees but directed along the direction we were entering the runway in. i.e. The parallel component would point in the take-off direction &amp; not against it. 

Made me wonder: Are there instances when lined up aircraft have to be made to taxi to the other end of a runway due to a last minute wind direction reversal?

Never happened to me, nor seen it mentioned in any ATC conversations / videos online so made me wonder. 

Of course, if the parallel component is smaller than the allowable tailwind for the aircraft then  I guess it does not matter?
What you are describing does happen. The runway change is a major event at a big airport and it usually occurs once a day. This becomes a major transition because landing aircraft have to be switched to the other end. AND, areas served by a single approach control, the change has to be coordinated with the other airports. Note that lines of aircraft waiting to take off rarely occur unless the airport is very busy and has few runways.

Thus, the runway change generally occurs over time (half an hour). 

If there is a sudden, unpredicted wind change, generally, aircraft that are already at the "wrong" end of the runway are allowed to continue using it if they are able to do so.

So yes, aircraft will on occasion have to move to the other end of the runway.

I have seen this more frequently at busy general aviation airports than at commercial airport.