Obviously that is useless if Object doesn't actually contain anything useful.

The problem is that c++ allows for multiple incompatible "worlds" to exist:

1) the MFC world.
2) the Qt world.
3) the wxWidgets world.
4) the boost world.
5) the Microsoft Visual C++ world.
6) the Mingw/GCC world.
7) etc.

All these are incompatible with each other. Different ABIs, different built systems, different implementation details, different memory management techniques, different threading, etc. You can only choose one of them and be happy.

I disagree. You can't use one of these "worlds" with any other "world". In many cases, simply including files from two or more "worlds" does not even allow the program to compile (let alone function properly).

And then designing something that mixes features from these worlds requires extreme hacking techniques.

For example, Boost signals are incompatible with Qt signals. MFC and wxWidgets don't even have signals.

Or each library contains its own string class.

So doing computational simulations is no longer needed? You might think that's not important, but that is the cornerstone of my future research career. I want a language that works well with that, and the patches coming in C++0x are very much welcome to people like me. Perhaps business world does not need C++ anymore, but business world != entire world.

The difference being C# is still changing a lot, and can continue to change. C# is controlled mainly by Microsoft, so they don't have to deal with standards committees and a bunch of whiny nerds when they want to change or add something.

C++ has not outlived it's purpose. You said that, I corrected you. No false dichotomies introduced.

I'd like to see some proof of that. Academia has been creating quite a few innovative languages these days, irrespective of their business applicability. FORTRAN is still going strong in the academia too, being revised and updated constantly. I doubt it even registers in your little percentage growth chart.

I think that the business world fuels the evolution and adoption of programming languages in the business world only. Business world != entire world.

When it comes to business applications, C++ is not relative any more. But there is a lot more than business applications out there.

For example, one of our next projects at work (if we are offered the contract) includes the modernization and enhancement of software that operates the torpedo systems on a certain class of French Frigates (details can not be disclosed of course).

The software is huge. We are talking about 5 million lines of C++ code and 3 million lines of Java code.

Java is used for the GUI. Java apps are stored in a cluster of servers, accessible from any console on the ship. All the consoles are programmable.

C++ is used for the torpedo systems. The torpedo launcher kernel is written in Ada (a few hundred thousand lines of code), but the rest of the system is written in C++.

One thing that C++ has, and it is a tremendous advantage when compared to other languages, is performance. All the power of C++ comes from two things:

1) templates. A list of integers works in C++ many times faster than a list of integers in Java, simply because Java has generics, not templates. In Java, a list of integers is actually a list of Integer objects.

2) static allocation. Much of the data in a C++ program live on the stack. Especially small classes used as keys to maps, iterators, etc. Big win for C++ in this domain.

These things matter very much, especially when there are run-time constraints.

So, overall, C++ is still relevant. It may not be obvious, because C++ is not used in business applications, but it is here and it is not going to go away anytime soon.

C++ is also used in all the major applications:

http://www.lextrait.com/vincent/implementations.html

So I don't think C++ is moving into a niche any time soon.

Open Source, yes. I can see why: An open source project needs as many contributors as it can get, and C is somewhat the lowest common denominator for most programmers.
Also, the number of new open source projects doesn't really say much: Many of those end up as abandonware, or they never find a significant audience. Also, most open source projects are *nix-ish things: small tools tailored for one specific sub-task; this is something C lends itself for.
However, if you count the total number of users, and include web applications, then I bet the figures look a lot different.

I still think that C++ is slowly moving from its pole position as the most popular general-purpose programming language towards a more specialistic role - when runtime performance is more important than developer efficiency; when legacy C++ code needs to be supported; when coding at a very low level is necessary; when JIT compilation cannot be afforded; things like that. The process is obviously slowed down a lot because:
- Everybody knows C++
- Everybody has been using C++ in the past, and migrating can be costly
- C++ is available for virtually every platform

Speed doesn't matter in most cases. Only in special cases would the slight speed hit to a different language matter.

Speed doesn't matter in most cases. You are mentioning huge applications. How many good office programs, databases, and browsers are there? Not many.

The vast majority of business applications do not require the marginal speed benefits of C++. And even of the three you mentioned, only databases would truly benefit from that. C# is more than sufficient for a word processor or web browser.

Ease of development trumps using fewer CPU cycles.

The language itself doesn't make the handling of such huge pagecounts slow, but rather their algorithm.