#warning rant coming
"printf instead of std::cout"
I love c++, but it definitely has some dark spots, even still the long overdue c++0x update (c++11 whatever). Thank deity we finally have standard smart pointers, better templates in various ways, move semantics, etc. It was really necessary to finally have that, even if it was a decade late (I'm sure we lost quite a bunch of good c++ programmers and projects to more newfangled languages in the delay). Even though we often won't be able to use it until all compilers (and developers) in use for a certain codebase are updated, it is a start.
c++ streams... After exceptions the second worst mistake in c++... c++ needs something good for that functionality, but streams and exceptions don't help.
Beware of std::cout, it is not thread-safe and is a gigantic pain in the expletive for outputting formatted text. The utility of overloading the shift operator for interfacing with streams is overrated. std::endl is a curse word. streambuf is an ugly hack.
while std::string is usually an improvement over the plain 'char *', it also is as often overkill as it often is underpowered. Why else would so many people have their own string class? Why would Qt have QString? It's because std::string and fstreams are severely lacking... standard c++ needs more syntactic strength in tokenizing, parsing, formatting, transforming, combining, and type-converting of string content. What is there, in the standard, is, well, imho kludgy. I'm not saying that I have the answer to what exactly it needs, it just needs something better.
c++ still has a lot of catching up to do. Libraries like boost should really only have their sandbox and legacy code left, and libraries like qt shouldn't need to redo/replace basic functionality. It should be possible to get a proof of concept implementation (aka badly optimized but mostly functional and not too many bugs for a demo or trial) working quickly as easy in c++ as it does in certain other languages. Until then, it should work hard to catch up before we lose most programmers to other languages.