In general, Qore's main development target is to provide a stable, powerful, and efficient platform for developing complex programs. Backwards compatibility is a very high priority, even for versions before 1.0, and "unrestricted" code (code not subect to parse restrictions) should remain highly compatible until 1.0 and beyond.
There is no stable list of features that need to be there before the 1.0 release; Qore is getting better, cleaner, and more powerful with each release, so sooner or later 1.0 will happen.