He has promised to nominate Justices who respect the Constitution. From everything I have seen, Roberts fits that very well. Nothing is certain, of course -- but to compare this to Souter the hermit is just plain wrong. Roberts worked in two Republican White Houses and clerked for Rehnquist. He's much better known that Souter ever was.
Stop confusing people with facts.
Good point...though, as a I recall, Souter also worked for Republican administrations and had a reputation as a deregulator among some.