Well I'm not sure since they're important characters in the Twilight series... if they quit, I'm curious what the story would be... If you're talking about the actors, I'd be annoyed because I hate it when they change the actors for a same character (like they did with Victoria for example) but I would still like the Twilight series...
No i would'nt, at least not the movies. They are two of the most crucial characters in the series - if they changed the actors, the series would lose a lot of credibility and it would be pretty confusing xD hahaha