Just received my new 800D V4 last friday.
It seems to have support for 1080P. too bad I don't have a 1080P device to try.

front panel display is
800_272

Information display

Firmware 2.18
Compiled 14-06-06
Microcode W-2411
DVS-LDR DSL-720A
Drive Code LV18
DSP1 Code 001E

I will compare this to the V3 that was upgraded to
V4 if I get a chance

The Scaler Menu has the opitons
deinterlace
720P
1080I
1080P
auto

I did notice some other small changes to the onscreen menus. HDMI/DVI mode seems to be gone.
May be auto negotiated via the interface instead of a menu option.

Brian

861v4, 800D, DSP5500 L/R G57, B&W rears,
Fanfare FM FTA-100, SIRIUS SAT RADIO, AppleTV, Comcast X1 DVR, Revox B215, Sony 60XBR800.