Sorry. We've already been using FP long enough to know that it isn't the next silver bullet. There is a well-defined body of problems which FP handles really well, but there's also a well known body of problems FP doesn't handle so well.
I don't think that's the point :-) I quite agree that FP is no more a silver bullet than any other development style. However, IMHO, FP has yet to have it's "silver bullet" moment in the limelight - which means that the really nice things that the FP style can give you still haven't been absorbed by the world at large.
Before the Java "silver bullet" I was always having arguments with people who said automatic memory management was impractical, and how VM based platforms would never scale for real world use. Despite the fact that people had been using them for years - decades even.
Post-Java these discussions have become a rarity.
In fact I think that this will be the lasting legacy of Java - it'll be the language that made garbage collection and VMs popular.
I still encounter people who think that useful bits from the FP toolbox, like lambdas, map. currying, etc. are a complete waste of time since they're not in their toolbox and they've never used them in anger. An FP language could do with a bit of the silver bullet treatment just to get useful concepts out there and in peoples heads.