this can be done with two good condensers too, using the real ear-distance of ~17cm and directions and a "ball"-characteristic (sorry, i don't know the correct english term).
makes cooool effects!
Omnidirectional. Yes, that's cool - i'd love to have an classical orchestra playing, and run across it with that kind of miking - unfortunately with the kind of records i'm working at (rock, rough and raw) that don't seem to be in the near future.
And now the direction issues...
Panning; that's of course Left and Right
Reverberation; that's Front and Back
Frequency; now we're opening a can of worms. The correct answer would be Up and Down, but psychoacoustics (i use this word everyday

) affect this so, that in some ways it also affects Front and Back.
Ok, now to the difficult part. You know when you're driving a car, and other cars pass you by; they sound like nyaWWWvouu... that's called the Doppler effect (same with leslie speakers and police sirens). That's sort of comb filtering, and by that sort of comb filtering you can do all kinds of surround effects. Psychoacoustics. Your ears tell by filtering, if the sound is supposed to come from front or back of you.
Other psychoacousticswise adjustable things are the compression timing and reverb predelay.
Sorry, got to stop, have a train to catch.