In reply to monkeymark: Thanks for posting, I haven't been down there lately. That'll teach me!
I also think it's something to do with high lining as someone has already stated. The fact that there are 3 threads suggests they are trying to create a system with some redundancy, and the style is tending towards some amateur pursuit rather than a professional purpose. I think there were 3 to 4 bolts put in when I posted last time, just lower down in the same area. This suggests to me the same people could be responsible. Now the threads are near the top of the crag, it is more achieveable to link a highline to the next arete and improves accessability to it. They may have also deliberately not placed the threads on Nightmare, but just around the corner, so not to p*ss climbers off too much.
My two penneth, for what it's worth. I'll try to get down there more often.