I'm thinking cross-promotion/using her casting as Eponine to boost Glee (not that it really needs more, I suppose). Fair point though.
Radcliffe as Marius? My first reaction is he's too young, but he's 21 now and only 3 years younger than Michele, soo... that could work, assuming he can sing. I doubt he could pull off Enjolras, but maybe. I still like Barrowman as Enjolras. Definitely too old for Gavroche.
Though that would make Anne Hathaway too old for Cosette I suppose? I dunno, maybe not (not IMO, but next to Radcliffe, perhaps). If so maybe her as Fantine? Though a bit young for Fantine maybe