I got the beta running (for those having troubles, you can just 'g' past most MacsBugs occurances), and here's some more interesting things I found in there:
The interface is butt-ugly (as Dan said). Except the main screen, which is just cheap-looking (probably built it in StudioPro in half an hour), though not ugly. The in-game interface is the same one seen in the early movies (see http://myth.bungie.org/legends/relics/unimplemented.shtml">The Myth That Never Was). Looks rather native-American, though that could just be because of the arrowhead-shaped map-disclosure-triangle.
Both "King of the Hill" (Grave/Spiderweb) and "Landscape" (an unseen map, though it somewhat resembles Gimble/Gyre from Myth II) work. A demo plays behind the main screen (once you've selected a level to play), though no actual action takes place - the game just shows different views and pans and sweeps of the map and the things on it. "Landscape" is a rather uninteresting map, other than it features fully-working (though silent) Skrael - in fact, everything but Dwarven explosions is silent, and those explosions are damn loud. Networking works, though it's TCP only, and I haven't tried it with other people yet (wanna do that for the next Asylum Night?).
Double-clicking doesn't select unit groups, but the number keys do (though they seem to select specific hard-coded types of units, not like presets as we know them). There are no formations. There are no yellow circles or red 'x's on the ground to indicate what you just told a unit to do (not even a flash of an enemy unit's border-box when you attack them). Your units are deselected after you order them to do something. There are no waypoints; however, you can control-click your own troops and your units will act as if you had ordered them to attack an enemy. Units' health bars appear over their heads. Gesture-clicking works, but the old TFL 1.0 way; a quick flick only, no arrow indicator, no option key usage needed.
F1 through F4 do nothing. F5 changes resolution, but there appears to be a problem rendering the overhead map in low res. F6 changes the placement of the status bar - top or bottom? (You can't get rid of it). F7 shows players - with "Human" and "Computer" shown in solo games. (Solo games, BTW, are simply netmap-games with an unscripted enemy placed elsewhere on the map). F8 does nothing. I don't think F9 or F10 do anything but I could have just forgotten. F11 shows details rendering stats (including stuff on the cool reflection code that was later removed). F12 toggles the "Crapalicious" debugging mode (I think I got that name wrong; crap-something). Tab toggles overhead map. Q/W/E/A/S/D/Z/X all work like in the standard release-version keyboard setup, but the zoom keys are reversed. (Mousing the top/bottom edges of the screen moves forward or backward, and the sides rotate). R toggles the "aggression" button (see below). There is no taunt or special action, though there are Journeymen (how do you use them, then?). F seems to toggle the overhead map. There is no scatter. Return-key selection of all units on screen is absent, but the spacebar-stop works.
The status bar is rather interesting. Instead of just a pause button, there are three button-spaces there. The far right is the pause button, though it doesn't work. The middle button is blank, and obviously does nothing. The far left button is what I've nickenamed the "aggression" button. It shows a Warrior just standing there; but when clicked, it shows a big angry warrior poised to attack. It appears to have something to do with auto-attack; clicking it twice with some ranged units selected sent them running towards the enemy on the other side of the map. However, I haven't figured out it's exact functionality.
If you hit escape in the middle of a game, you are presented with what appears to be a damage/time or kills/time graph, and only one button: "Yes" (which ends that game). Trying to hit escape again brings up Macsbug, and a simple "g" will not suffice; the game ends, the main screen fades to black, and then back in to the desktop. There appears to be no way to exit the game other than the escape key; even dying leaves you sitting there, staring at your enemies.
A couple last details: the Fog of War is absent, the field of vision on the overhead map is replaced with a little tiny arrow at the camera's exact map location, and while there is no camera-clipping, things off the edge of the mesh simply appear black, instead of all blurred like in the release version.
