The current stable -r1 only supports postgresql up to version 9.3. Postgresql 9.4 is stable now and supported by pygresql -r2. So, the missing stabilisation keeps postgresql:9.3 on the system.
Please stable: =dev-python/pygresql-4.1.1-r2
amd64 stable
x86 stable
alpha stable
ia64 stable
Stable for HPPA.
ppc stable
sparc stable. Closing.