I figure a math Ph.D. who's poked at Haskell and Django will be smart enough to figure things out, and enough of (the right kind of) programming is more about figuring out new environments than knowing an existing environment very well. The one thing I don't see in your writeup is any concrete experience to look at. Do you have some awesome Django site that does something nifty, or a cleverly-designed Haskell application, that you can show off? For bonus points, can you get real users?
The Stripe jobs page (http://stripe.com/jobs) has some programming challenges that are way too ambitious for a usual couple-hour coding challenge, but definitely along the lines of a nontrivial, self-directed project that I'd like to see. Spend some time over a weekend making something like that, and it'll be worth noting to everyone you apply to. I've also seen great websites explaining mathematical concepts in intuitive, interactive ways; maybe there's a paper or something you like that you can turn into an instructional webapp.
Since you've got a couple of years before you'll be applying, another great option is to get involved with some open-source software, preferably something you use already or would want to use.
Thanks, you don't see any concrete experience because there isn't anything worth showing. I'm working on some stuff right now to do just that. It's actually a webapp to allow teachers and students to communicate math effectively without having to know LaTeX and email pdfs.
From what I've heard so far, it sounds like there is definitely opportunities for me, and that means that I can justify spending time working on these types of projects over the next couple of years.