Edit: some additions for clarification
The irony is that I teach a lot of Python programming classes. And despite that, and my love of Python, I think it's a shame that they no longer use Lisp (or Scheme, or Clojure) for the equivalent of 6.001.
Python is easier to understand and get into. And Python has some amazing features that you want, such as first-class functions. And it's a real-world language, which you can't say about Clojure, even with its growing popularity. And Python is my strong recommendation for everyone's first language, because it's so easy to get into.
But there are some things that are just easier to understand in Lisp than in other languages. Implementing Lisp in Lisp (metacircular evaluator) is a fabulous way to think about programming languages that is harder in Python than in Lisp. (Not impossible, but harder.) Lisp allowed us to think about programming in all sorts of new ways, because it handled so many of those paradigms so well.
So I still think that the intro CS class should be in a form of Lisp, because it opens your mind up to possibilities. But if you're not going to go that route, then Python is a terrific first language, and I'm quite happy to see it getting the attention it deserves.
It's relatively new, but I'm really excited about it, and that is what I'm learning, it allows you to get the benefits of learning lisp and python at the same time. It's compatible with python in both directions, so you can use it in any practical project - with django or with machine learning libraries, etc.
I think it's really cool =)
Or is it to teach the fundamentals of programming? Then Scheme is the ideal choice, but they should map concepts to mainstream languages. I.e., here's how OO works in Java, now we'll simulate it in Scheme. If more people took a course like this, we'd have fewer language fads IMO.
SICP is such a great book, it is a must have for programmers...
So the question is really: can you use Python to get most of the benefit of teaching using Scheme while at the same time giving the student a practical tool for future use? I haven't taken the new Python courses, so I don't know how well the material bends to the language, but I remain skeptical of the "most of the benefit" part. Maybe I'm just a curmudgeon, but I sort of think they should keep Scheme and then just have a short (e.g. over IAP) course on practical programming techniques using Python (or whatever). Or maybe someone should rewrite SICP in Clojure? Finally, I know Scheme has continued to evolve, and I wonder if it's really still true that Racket is impractical as a day-to-day language.