In reply to colinmcmanus: I was just over for the holidays, and what I can say is that there's plenty of new sports routes being put up in the last year. Not sure whether an updated guidebook has been published - think the last edition was 2007, so there's a lot of new routes not in that book.
The major sports venue is Wied Babu close to Zurrieq, with routes for everyone there on both sides of the valley. Other worthy crags would be Lapsi and along the Victoria Lines in the North. There is also plenty of bolts on Gozo (the neighbouring island).
climbmalta.com and www.maltaclimbingclub.com list a lot of the bolting updates - can try contacting them too.
I'm sure there'll be plenty to keep you occupied for a week!