I think the XP-8 is going to "grow" over the next few years and become very powerful.  Like Cory said, it's not a hardware limitation, it's software.

Anyone else notice the "analog" labels above the sense input terminals??  Hmm...

For right now they are a tad behind the times.  That's not necessarily a bad thing.  We sold Denon for a while because they were so feature packed.  Then we had a bunch of equipment issues and switched to Marantz.  Marantz was nowhere near as feature packed (an in fact was a harder sell because it didn't do everything the Denons did) but guess what?  Zero equipment problems the whole time we sold them. 

I'd rather have a super-solid control system in another 1-2 years than rush and get something half-assed.  There's enough of that on the market.