Sony has now backtracked even further on internal dts-MA decoding. The features page on the S550 at SonyStyle used to say dts-MA would be available with a firmware update. That language is now gone.
So, the initial announcement for the player said it would include dts-MA decoding. Then, Sony said dts-MA decoding would be delayed. Now, it's not even mentioned. The player is described as having TrueHD decoding with dts-MA available via bitstream. That's kind of distressing for those of us who need to use analog for lossless audio. Panasonic may have the only moderately priced player with dts-MA decoding for awhile.
With analog, you need to tell the player about your speaker arrangement, much the same as you do when setting up a receiver. If you enter a 5.1 configuration, the player will downmix 7.1 sources to 5.1 so that you don't lose the audio from the unused channels.
Analog also means the player has to handle bass management and other similar tasks that are usually handled by the receiver for digital audio.
Ah, thanks BIslander! That makes sense to me - about how the 7.1 channels can get downmixed to 5.1 so one doesn't lose audio information.
What doesn't make a lot of sense is what Sony is doing! They'd got a feature, then they'll add it later via firmware, then they won't mention it at all. That's nuts and messes up my buying decisions and those of other people, no doubt. Thanks very much for the "head's up" on that! Maybe that Panasonic BD55 is in my future yet. BTW, I got the new Crutchfield - they generally charge full list price on everything - and they've got the Sony 550 for only $399. That sounds good but not if they are chopping features!