I am absolutely disgusted by the number of people on this thread who seem to be threatened by the idea of encouraging an early interest in CS. I've been volunteering with Hour of Code this week, meaning that, unlike everyone else I've seen on this thread, I actually have some first-hand knowledge about it. I've done the exercises myself, and have seen kids using them start to "get it". How many of them will keep with it? Idunno. But if more kids get into coding because they were given the right tool or had access to a CS curriculum earlier, and they keep exploring it, and that leads to more developers on the market, if they have half as much fun getting there as I did, then that's awesome. I'm not a big enough asshole to value my own special snowflakeness over exposing kids to as many opportunities as possible, and I'm ashamed of how many people around here seem to be.
As for those who scoff and turn up their noses at drag and drop interfaces like Scratch, oh man... where to start? First, it's an INTRODUCTORY tool. Nobody is pretending that this is what professional developers do. Second, it's an excellent way to provide that introduction! Your first language is often the hardest to learn, right? Why? Because you're not just learning the language, you're learning how to think like a developer, how to break down problems and structure solutions in a particular way. Language is an implementation detail. Thus, tools like Scratch abstract it away so you're dealing with the most essential presentation possible of concepts like variables, control structures, and so on. You get that down first, then you start writing "proper" code. IMO it's a brilliant approach.