snes: composite, s-video
n64: composite, s-video, component?
gamecube: composite, s-video, component
wii: composite, s-video, component, Hdmi?
ps1 and ps2: composite, component s-video..
ps3: composite, s-video, component, hdmi
xbox: composite, s-video, component, dvi
xbox 360: composite, s-video, component, dvi, hdmi (gen2)
dream cast; component, s-video?, component (for earlier cd based sega hardware you'll need to check what's available in the way of connections and cables..)

from game cube to dream cast you will need to check what analog audio connections are supported via adapter cable..

though you can see what i'm getting when talking about legacy support especially if you want multi channel on cd/dvd based consoles

I wasn't looking at spanning across hdmi for pj use, I was more thinking about doing a format set per pj..
in the case of lcd tv use, I was using 1 as a movie display whether if be connected via hdmi or via component
1 set for 2:40, 1 set for 16:9, the last set for tv....

the only time i would consider multi spanning across pj's is if i had the space to do an omni/imax type layout..

i'm trying reduce using external av source splitters as i'm already using this method and there little way to control the unit with irhd and would you like to have a rack full av switches to support 15-30 odd consoles

if I wanted to greedy i could of said whack in analog tuner to cater all the rf based consoles..

RIHD isn't just used by onkyo. jvc, sharp and sony use it for universal control for all in 1 switch..

would you really need analog audio connections for every device that supports 5.1-7.1 or better surround modes...

composite is dead for years.. as long as it doesn't require anything above 640x480 res..

S-video isn't dead just yet, 720i and 720p will be possible, you might be able to do 1080i at its max throughput, though 1080p will be a nono due to hardware limitation..
component will be the last to die as it can support up to 1080i..
scart is an unknown entity
hdmi is going to be king for the foreseeable future though i don't see the console makers will look at porting their older console to hdmi..

console usage is only 1 option of end use of the processor/preamp