His reasoning is obvious -- it's an effort to show that he's firmly in control, that his Cabinet selections are on track, and to reassue a nation anxious about the economy (and now, perhaps, terrorist threats). Incidentally, it's also a nice opportunity for the media to worship its idol.
But there is a potential downside to all the visibility. Even people who voted for Obama don't want to see and hear from him all the time. They just want him to do his job. And just as it's easy for the president of a volunteer organization to become enamored of holding meeting after meeting where she will lead the discussion, it's easy for those in political leadership to begin to believe that normal people share their interest in the minutiae of governance.
It's likely to become a particular trap for someone like Obama, who's regularly treated by those around him (in the press and elsewhere) as though every word he utters has been carved in stone and brought down from Mt. Sinai. It's worth remembering: Most people aren't that interested in how the country's problems are solved. They just want them solved, and as quickly as possible.