Yes, it can be argued that Arrow isn't quite as popular as it used to be, but I don't think that anybody has mentioned that it will be building a coaster at Kennywood Park to take the place of the Steel Phantom. (Yes, that grey and black baby of mine is gonna be gone, with something in it's place in 2001.) Keep your eyes on this.
For those of you who've been on the Steel Phantom, you know that the landscape is used fantiasctically. After the second hill, you drop straight down off a cliff, and above then over the Thunderbolt (which, also, greatly uses its landscape to its advantage).
My friends and I have wondered, first off what TYPE of coaster will go in SP's place, second, what kind of DROP will there be? If they use the drop where the current SP 2nd drop is, they can easily bring that up a bit more and have a competitor for the tallest coaster in the world. The problem, however, is land at the bottom of the drop. Pretty much after that drop (that I'd like to see), it runs out of room! So, I suppose, they're going to have to go out over the Monongahela River. If they do this, they'll be able to have a huge drop with not too many nasty G's at the bottom of it.
Well! After reading all that, let me finish by saying this: Arrow definately has a project on its hands, and it just may end up leaving the Millenium Force the former tallest coaster in the world.
...just my thoughts ;)