LOL! Two months ago, Contrail67 called me an 'eeyore' because I didn't expect a JCBA by this October. Are you hinting that I've got rose colored glasses on because I expect a JCBA prior to summer 2013?

But to the crux of your question:
Last year, it became clear that LUAL and LCAL IT integration was going to take longer than expected - completion sometime around fall 2012. Because there would be no/very little pilot synergies until after IT integration, there was no financial incentive for management to sign a JCBA prior to IT integration.
The second issue beyond IT integration is age 65 retirements. It would be in management's best interest to have a JCBA prior to the retirement cycle restarting. Retirements will create utilization issues that can be reduced with a JCBA.
Management is now getting more serious about negotiations, likely targeting late fall for a TA. I expect the first TA to be voted down so tack on another 3 months or so before TA2. I'd hope that issues are worked out with TA2 but I've padded my guesstimate in case we have the second TA voted down.

I've had the same expectation for a JCBA for a long time: very late 2012 to summer 2013. Some are going to view my range as overly negative; others will view it as overly optimistic.
My expectation is based on looking at this issue from management's point of view. Management isn't going to hurry to sign a pilot contract that increases their costs if there are no synergies created. Once there's an incentive to reduce overall cost, they'll get serious about a JCBA. Based on the number of updates on unitednegotiations.com, it looks like management is starting to get interested in a ratified JCBA.

The above is just my opinion.