Up until recently the quarry has only been home to some loose and dangerous trad routes. In June this year the bouldering potential in the quarry was realised by some enthusiastic locals. See North Wales Bouldering website from a topo download: http://www.northwalesbouldering.com/newsitem.asp?nsid=411
On Wednesday I went to check out the new problems. They're great! Pads and spotters are essential items as the landings can be bad. Highlight for me was Cruiser Weight V9, which probably isn't V9 but its still a great problem. Unfortunately Chummer's Wall was wet, it looks amazing.
I have updated the UKC crag page from Moel Y Gest quarry: http://www.ukclimbing.com/logbook/crag.php?id=816
There is possibilities for bolted sport climbs on the more compact sections of rock in the quarry. This is controversial but I think it an only improve the quarry, since no one climbs the routes there (for good reason!) at present.
Cool looking unclimbed arête
View of Cnicht and the Moelwyns from the quarry