As a person, it's awesome. I've met Jansen before, and let me tell you, it's really hard to dislike the guy. He's well-spoken, nice, and down to earth. I'd bet that anyone on this board that sat down and talked with him would enjoy the experience. As a Dallas fan, I can say he is my "favorite" (And I use the term loosely) Commander.
That being said, I don't think it's a great move on the Commanders' side. Jansen was pushed around a lot this past year, and you can tell his legs aren't nearly as strong as they were in his first 4 or 5 years in the league. He is a high-character guy, however, and those are always good for a team.