Really? I spose most modern metal guitars from Jackson, Ibanez etc... mostly have rosewood or ebony boards. And of-course maple fingerboards look daft on a Gibson style guitar. I always favour (why is it trying to spell-check that? Silly american software) a maple neck/board for feel and yea, it seems to add high-end and spank/cut. Kinda like ebony but without the really fast attack. I'm sure a luthier like Jon could tell you what's actually happening.
Most guitars I see in person are either Ibbys, PRS, Gibsons, LTDs and such which as you say have rosewood or ebony. I only see maple on Strats, Teles, etc, so basecally the Fenders.
I agree that it looks really cool on LP types, but it is so rare that I have only ever seen it on the internet.
Ebony without really fast attack sounds really interresting.