Muse should be.
They have the slow and the fast, the soft side AND the metal side, and even the classical piano side.
Their songs are incredibly original, but also have influence from bands like Queen, Pink Floyd, U2, and (I guess) a little bit of Radiohead.
Songs like Map of the Problematique, Stockholm Syndrome, and Knights of Cydonia can (and I think will) blow the roofs off of American stadiums and arenas in the near future (assuming that they have roofs).
Their drummer is absolutely amazing.
Their stage presence is excellent. Their background visuals are awesome, but not over the top.
They have the musical range of a band like U2. They can play a song like Citizen Erased or Assassin, but also a song like Soldiers' Poem (a la U2 with, say, Mofo and The Sweetest Thing.
So, Muse is a very worthy candidate. The interest in America isn't here yet, but I think it can be soon. Most of this country might point to a band like RHCP to be the next to carry the torch, and I'm not saying they won't.
But Muse is awesome, and I hope they can rise to this level in areas other than Europe.