Simply put necoicould, PR1.2 contains what is called "Qt" version 4.6, which all new software is being coded in. The problem that is started to occur is software development is grinding to a halt because version 4.6 only comes out when PR1.2 comes out. So essentially we cannot move forward with improving N900 software until it's released.

Hence why the anticipation for it's release is so large. There are already applications sitting in the development repository that you are unable to install because the N900 does not have Qt 4.6.