When does the current contract end?
It doesn't end, but rather becomes ammendable, as early as 2013, or as late as 2016. That is one of the concerns I had about IBB. Possibly a 9 year agreement with zero COLA and small longevity increases that don't keep up with the modaest inflation we have now.
If upgrades continue to elude us, there will be a large number of SICs that will get zero increases until a new CBA is agreed to, which is likey to be well beyond the ammendable date. IBB won't be as popular then. But who knows. A lot can happen between now and then.