But what I'd really like to see and what I'd definitely pay a lot of money for is a Head First C++. Think about it: C++ is a widely-used programming language in universities, applications, or even competitions. So I'd say there are a lot of people who would benefit from such a book. Not to mention that O'Reilly has an awesome unjustified lack of material when it comes to C++. Most of the books are poorly written, have outdated code, and all that stuff.
Moreover, the most important thing in learning something is getting the basics of that something, and this is what a Head First is the best at: teaching you the basics in a manner that will make you learn, understand what you're learning, and want to learn even more, when you've got to the other cover of the book. This is what makes the Head First series one of the best series in the industry of computer programming: covering the basics in the best manner, so that further, more advanced refference books on that topic are easier to digest.
Also, I hope you're not going to consider this as being rude, but in my opinion, a book on C# is a waste of time. Why? Because C# is a platform-dependend language, while C++ is widelier-used, cross-platform, etc...
So... when?!? The guys at Head First should just read some of the opinions out there: most of their progrmamming books have many comments begging for a book on C++, the forums all full of people yelling for a HFCPP, and if you search for "Head First C++" on Google, the results don't hold back from popping-up.
Please, everyone who loves the HF series, let's gather as many posts as possible, and let's keep this thread on the top of the list. Maybe one day soon...
I agree with your above statement completely. This is what I enjoy most about the HF series. They are a great primer to more advanced books on the subject matter.