AFAIK the current system is Debian-based. This means that it uses the Debian's system (packaging) and all the split packages. For example, KDE is split into a number of packages for Debian. This also happens for a number of programs and libraries Maemo uses. Switching to RPM doesn't mean only that the system will be repacked with RPM. It also means that another distribution will be used, meaning (among other things) that libraries will not be split (the same way) and that not all configuration files will go into /etc.

Take for example /etc/network/interfaces. This is debian specific and most probably will be different (or don't exist) in Meego.

In other words: Debian goodies (except from packaging) will be gone.