I don't even understand why there has to be a blog post about this. When you make a major investment in a technology you don't just wake up one morning and rewrite it using another one.

Thats how you lose money and your competitive edge ... I had a small PHP app that I transitioned to Ruby on Rails ... it took 2 months (mostly because I was doing it part time and was only just getting serious with Rails) and that whole time I was falling behind to a competitor because I wasn't adding new features and fixing bugs.

I'm glad I did it in the long run, but still ... rewrites to take advantage of the flavor-of-the-month technology can be very overrated.