Don't necessarily look at what they encode with but rather what source they encode from. Typically they work from film quality sources; much, much higher quality than DVCPro HD.
The systems they use would likely be something like Sonic CineVision, CinemaCraft or completely in-house only bespoke systems not available to the public. (Apple use compressor to encode all the movie trailers on their site, but are very strict about the quality of the source they use).
The compressionsts they employ to drive these systems are experts in their field and use techniques like complex segment re-encoding to get the best out of the bit budget.
"There's no chance that the iPhone is going to get any significant market share. No chance."
Steve Ballmer To USA Today: 30 April 2007
"We and Apple are neck and neck and we're chasing the two
Steve Ballmer, referring to Nokia and Research in Motion. October 6th 2009