Do not forget Qt/Python and remember, in programs where is lots of dynamic memory handling (like www-browser), Java and Python can have faster and more energy efficient programs than C++. C++ has its benefits in low level programming, but it is a previous generation programming language and has the crosses to bear.

RPM is an improvement. De facto security policy with DEB-packages is not to have embedded GPG-signatures, but RPM packages distributed are generally all GPG-signed.

rpm-program also natively support GPG- authenticity and -integrity checking of installed files (rpm -V), just because it is assumed every RPM-package has the GPG-signature embedded. DEB-packages and dpkg does not have this important security feature, but is added as a "plugin" and most of the Debian based systems do not use it. Also the old detached GPG-signature of some package is not found from the system after repositories have upgraded their packages, so to check after intrusion what was tampered is very difficult in DEB-systems.
So security-wise RPM brings lots of needed improvement.

Also RPM is the LSB-way to make Linux-systems more compatible with each others.

Yum, I think, is not used in Meego; but zypper, which supports differential-packages and therefore are better for users doing updates OTA in cellular networks.