My SWAG is August 2, 2001!
Actually JonB, when the contest started we had a 50% chance of completing it when the keyspace was 50% exhausted. Now that we have completed 35% of the keyspace, we have a 50% chance of completing it when the keyspace is 67.5% exhausted. 67.5 = 35 +.5*(100-35)
ScienceWhiz, the current 14 day average is 43,471,877 WU's/day. Without allowing for growth, it will take 1022.5 days to exhaust the keyspace. Allowing for a growth rate similar to what we have experienced already, it should take 507.4 days to exhaust the keyspace.