I recently rewrote a huge PHP application in D2. It isn't a completely fair comparison, since the PHP was written by, well to be polite, PHP "programmers", but the results were pretty astounding.
90% reduction in lines of code [!], 200% improvement in speed under heavy load (only 50% improvement under light load, still good, but not as good), and the code is actually maintainable! Also, the original took about a year for the first team to write. My D rewrite took 6 weeks. Oh yeah, and the PHP is riddled with security holes. Not so much with the D. The best part about the speed is that it is just running as plain old CGI and my code does a lot of inefficient looping through XML. I could probably double the speed again by improving that. I might be able to write this into an article, but what I've done so far is just showed it off to other coders in some private messages on forums. A complication in publically showing it off is it is closed source though. The speed advantage isn't apparent until the code actually does something; PHP is much faster for hello world, but gets spanked when it comes to the actual work.
