I would SO watch an Oberanime :>>>
My personal reccomendation would be to have GAINAX do it...but then, that's soley because I love their work on Neon Genesis Evangelion. (you should check that out, it's an awesome show)
I love how Hideaki Anno and Yoshiyuki Sadamoto did Eva...I think they'd do a good job on Obernewtyn.
As for art style, I'd think something less frivolus than the typical shoujo mangaka would be fitting...I like the styles of Akira Amano (REBORN), or better, Takeshi Obata (known for Death Note)...I think I would prefer a shounen sort of look for this...as long as they don't over-endow Elspeth!!!
OH, ohohohoh....Has anyone else seen Night Head Genesis? That'd be an awesome look/feel for Obernewtyn (maybe if it were toned down a bit...pretty dark...). It's all about psychokinetic abilities/brain powers. I really enjoyed that.