They had 3 clan challenges this week for MW3 (one of them being tomorrow). They also posted 2 clan ops for MW3 this weekend (Sat @ noon and Sun at 4pm CST). This is for the Xbox 360 and I would assume is also on PS3. They aren't dead, but they have reduced the number of clan challenges each week. I expect it to continue to be phased out and some suspect it will be gone completely by sometime in March.