Difference in July blu-ray and December blue-ray?

I was lucky enough to get in on the pre-order from speedgear.com to get the Senna blu-ray here in the US. I received it arond the last week of 2010. Now I've read articles that seem to point to the blu-ray released earlier this month as "the best possible version".

Now, I remember Speedgear telling me around early december that it had been pushed back until 2nd quarter of 2012, but then I got an e-mail a few weeks later saying it had been shipped.

To top it all off, a month ago or so the official Senna facebook page had an article saying "Senna blu-ray finally being released in US" or something to that effect, pointing toward the July release.

Is there a difference in my December blu-ray (that includes the additional footage that wasn't in the theatrical cut) and the newest blu-ray release?

Or is this just some sort of PR/region cluster****?