A digital input on a future pre/pro (for use with DVD-A/SACD, separate from the coax and optical digital inputs were already used to) would very likely not use a standard coax or optical digital connection like we use now. It's not certain, but some of the things I've heard suggest that they'll use something like FireWire as the interface.

Thanks gonk for the links on THX EX and DD EX.

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