Actually the Marantz pre/pro is $2,599.99 ($5k for both pre and amp). Just is good?, I'm sorry but I have to disagree on that one.

The Marantz separates, like the Integra separates, are a LOT of bang for the buck. But once you actually dig into each a bit deeper, the differences are more apparent. Like was mentioned, the Denon has 6 HDMI ins where the Marantz has 4. But that's only part of it.
Here's a rundown of the many things the Denon AVP offers that the Marantz does not:
Fully balanced dual differential design
4 DAC's per channel on all 12 output channels
12 balanced XLR pre-outs (3 for subs)
A/D conversion for EXT IN.
Silicon Optix Realta HQV video processing
4 Coax and 4 Optical Inputs
4 Optical outputs for other zones
4 Trigger Outputs
Wi-Fi connection
HDCD decoder
And one other thing that might not be a biggie for some, but for me it is, is the fact that the Marantz is "Made in China". The Denon AVP is Made in Japan.
This is in no way to make less of the Marantz separates.

The Marantz separates are going to give the Integra separates some serious competition. Both are reasonably priced, and offer all the latest decoding and HDMI 1.3 switching. And for many that are wanting to make the move to true separates, these are going to be the ones to beat. I mean 5 grand for pre/pro and amp, that's one hell of a great deal!
I only mentioned what I did to clarify the differences between the Marantz and Denon.