This is just my chiming in randomly from reading around so it's not the most informed opinion. In terms of cost, I think the 8801 is aiming more for people who would buy ultra high end instead such as McIntosh, Classe, Mark Levinson, etc. In comparison to those marks, the Marantz is a bargain. It has 11.2 full balanced out which is something I haven't seen anywhere else and it's the only Marantz (for now) to include Audessy XT32. I would guess this is geared for those who want the full super surround that 11.2 provides while using balanced outputs and have the highest end calibration for your ultimate surround sound experience. Compare it was the 4520 for example and you lose the amplifier but gain full balanced outs. I've also heard that the DAC is 32 bit vs 24. TL;DR maybe worth the price?
Marantz SR-5007 Klipsch WF-35, RP-450C, WB-14 theater
Marantz 2325 Klipsch Forte ii stereo
Sony PS3, Xbox 360, Wii U