How will Qt 5.0 be packaged for Raring?
Solution 1:
Library package names in Ubuntu include the major abi version. Some examples are libc6, libkrb5 and libqt4. So the Qt 5.0 libraries will be libqt5-*. Naming them libqt4-* would be wrong as they are not backwards compatible and packages depending on Qt 4.x would suddenly stop working if Ubuntu would do this. Naming the packages libqt5-* (and taking care of possible filename clashes) allows them to be installed simultaneously so you can run Qt 4.x and Qt 5.x apps on the same machine.