For all those of you who hope for massive air, I'd say, don't hold your breath.
Millennium Force has only two big air hills, for several reasons:
Cost and space.
Remember, when going at a speed close to 100 mph, you'd have to build very tall in order to have a hill of acceptable intensity. When going down from ~95 meters, I'd say a 60 meter hill would be sufficent, give or take ten meters. Another 60 meter hill, with supports, is almost as expensive as a lift hill on a regular Hyper Coaster, and would need to stretch at least 100 meters in one direction. If you were to continue along the air route, you'd need at least a 50 meter hill following it, again a massive investment in steel and room. And at such speeds, the turnaround needed would have to be huge:
http://rcdb.com/m/ig699.htm?picture=3
Thus, for space reasons, an overbank would be the best choice, preferably coming straight after the almost 200 meter long lift hill, so that you don't occupy too much land in one direction (an issue for many parks).
However, this overbank would have to be massive:
http://rcdb.com/m/ig594.htm?picture=16
And steel doesn't grow on trees, either. You would need to shell out quite a bit of cash for the supports, increasing the cost of the coaster, but sparing room.
OK, so now we can get air hills, right?
Yes or no. Intamin have proven, several times, that if you are going for airtime, you might as well buy a smaller coaster, look at the Mega-Lites and Balder, for example. Both would be quite crap without airtime, so no doubt that's the selling point. If you want airtime, you can get it in a smaller package. However, there's one factor you can't get on a small and cheap coaster:
Speed.
No launch coasters can give quite the same experience as Millennium Force does. You get a great overview of the area, then rush through it at breakneck speed. A launch coaster can give swooping turns and high speed, but when you get to a certain size, their main goal is the launch, perhaps a tophat, then the job is done. For launch coasters of a certain size, it would be too expensive to build anything more than a launch, something tall, and brake down. It's thrilling enough as it is anyway.
However, a Giga Coaster can't just be a hill and a brake. And as previously stated, we can't have too many air hills either. So what to do then?
Use what you have. A turn at 100 mph is thrilling, everyone knows that. And you can hug the ground, eliminating the need for tall supports. Cheap and thrilling. Good. And you sustain the speed as well, something the accelerators tend to neglect. However, you can't keep turning forever, the forces or the space used will be a pain after more than 90 degrees.
Then, you can throw in a hill, giving enthusiasts the airtime they desire. Good. But at speeds like that, it would have to be large, and occupy lots of room in one direction. So you have to turn after a single one. Time to put in another turnaround.
After this, friction has done its work well. You have a lot less speed to work with, and can happily put in another hill. Three, even, if you...
No.
For most people, dropping ninety meters and turning around at such speeds more than fill up their daily adrenaline dose. Already, you have turned a lot in their stomachs, the riders are shaken now. Another three or four doses of high G will sooner or later produce the substance we know as vomit. Or people will faint. One hill will do, then you can play on with high speed. But you can't do anything extreme any more. Not that you have the money either, turns at that speed requires lots of track, again requiring money. And you don't want stacking either, so you'll have to get a block in here soon.
Now you can either put in an MCBR, or call your layout a day. With an MCBR, you have more to play with, but you can't, as stated, keep going on with the layout forever. So you might as well get back to the station now. Give the people airtime on their way back, but if you already have shaken them up with strong air, I would recommend toning it down now. Then turn around some way, and on with the brakes. After all, you have lots of speed left if you dropped the MCBR.
See? You don't really have that many options. Don't be surprised if this turns out to be a near-clone of MF.
It will still be awesome for those who like MF, though. And the drop is almost bound to be a beast.