Personally I think that The Miz is the right champion for RAW even though it is the Road to Wrestlemania. For a couple of years now the RAW title scene has been quite stale as Cena and Orton have dominated the show and PPV's. Some newer names like CM Punk and Sheamus have been elevated to the mainevent on RAW but recently their storylines have pushed them away from the title scene.
The Miz has been huge since coming to RAW and his rise to champion has been steady, it wasn't an overnight success. He won the US title and MITB and held that for some time before cashing it in. He has been good as champion so far and as champion he has been getting WWE more publicity than anyone else other than Cena. It was time that WWE took a bit of a risk and went in a different direction before WM rather than sticking with the same formula year in year out.