George clones can't sing, can he? He can act, sure, but Sinatra was certainly more than acting.
Not many names spring to mind as being able to cover both bases really well. Hugh Jackman can, but he's a different sort of actor. And then there is/was Kevin Spacey, a very good singer of swing tunes. And Neil Patrick Harris can do it all, but again a different style of actor.
And in terms of singers who can act a bit, two spring to mind: Justin Timberlake, and from the swing style: Harry Connick Jr.
But in terms of acting, yeah, clooney's probably the closest in terms of who I could see playing those types of role, although Brad Pitt isn't too far behind, I don't think.