Yes, most recent TV's have multiple video inputs. Most recent sets have 3 or 4 HD HMDI video inputs, a couple of HD component video inputs, a couple of SD composite video inputs
If you have two HD DVR's the output from each one would go to a different input on the HDTV, DVR1 to HDMI 1, DVR2 to HDMI2 etc. You then use the TV's input selector to choose what input you want to watch.
The only problem is the remote control will control both DVR's as the codes are not selectable.
As far as the input to the DVR's place a 2 way splitter in the line from the TV wall outlet, and one leg to each DVR RF input port.