Actually, Ed's response to 8291 is, as Connell said, is
*** OH, YOU CAN STILL HEAR ME? GREAT! ***
so it isn't a generic but a specific to "8291" one.
Among other current responses are
FIRE - "*** closer ***";
BREW - *** --shiver-- ***.
Also, according to
http://oddworld.wikia.com/wiki/Soulstorm_ARG
there was once /soulstorm/ed/abeface1.mp4 file, which decoded to
"I CAN HELP YOU KNOW THE DATE". There's currently no use to this phrase.
And now we got Abe's face image... perhaps there's connection?
Also, looking in second Abe's eye, looks like there's a lot of glukkons, or mudokons, something like Paramonia/Scrabania temple to the right and something like tall building or net or something to the left...
Oh, and I don't know if it has any meaning or something, but on Soulstorm site in source code link to the CSS file adds random, most of the time 3-digit, but sometimes 2-digit number as POST-parameter after every reload
link href="css/stylei.css?random=552" rel="stylesheet"
after reload:
link href="css/stylei.css?random=159" rel="stylesheet"
and then again:
link href="css/stylei.css?random=581" rel="stylesheet"
etc.