It appears that in the world of programming something comes up once in a few years and is believed by many to be the "silver bullet". OOP, Agile technologies, etc. But generally, a lot of hype is generated for a small merit.
There is no silver bullet, but from each such hype we learn. OOP isn't a silver bullet, but we do gather a few useful techniques and design ideas from it. Agile/XP isn't a silver bullet, but it also has many interesting ideas.
Lets just say that if a new "silver bullet" is on its way now, I sure hope it will be FP - it has marvelous lessons to teach any programmer.
Update: I forgot to bring your attention to the fact the Church's thesis certainly doesn't say that "all computer languages are equivlent". A more or less formal defintion would be "any real-world computation can be translated into an equivalent computation involving a Turing machine".