I love public speaking... but only when it's me talking about something I know a lot about.
I don't think it's impossible for aspies to be in the spotlight, albeit I'm aware for most it would be daunting. But for me, it's only awkward when I feel out of my depth, if I'm talking about something I know little about, because then I feel as thought my every word and move is under scrutiny.
When I'm discussing something I know a lot about, it's different, it's like I become possessed. Almost as if the shy, awkward and insecure side of me that can sometimes take hold completely disappears. I talk with my hands, eyes have a burning quality (allegedly) and most of all I get into a "zone" whether if someone tackles me on what I'm saying, I can be extremely quick and witty in my retort.
I think, like you say, because you could practice beforehand, you could become well acquainted with the material and that would work wonders for your confidence when actually speaking about it in front of others. There are only two other issues I'm guessing could pose a problem, with most aspies it does - the eye contact problem and also feeling awkward about where your hands are. As I say, if you manage to "talk with your hands", move them in sync with the points being put across, although not to the extent people are thinking you're having some sort of fit (too much flailing of the arms throws people, believe me ). Eye contact can be difficult I'll admit, but just don't focus on one person for too long, if you see how politicians speak to a crowd, they're not looking down at thier feet or up in the air, they're kind of "scanning" the crowd, looking from left to right and so on.
Hope I helped a little .