petsc 3.7.5+dfsg1-2 is now uploaded and built in unstable. I also uploaded slepc 3.7.3+dfsg1-4 to unstable, which is now built on all arches. slepc needed a dependency on the patch release of petsc, because of the PETSc version reference placed in the pkg-config file SLEPc.pc.
Reviewing dolfin, getdp and deal.ii, they should not need a binNMU since they depend on the virtual package libpetsc3.7, which is provided by any patch release, libpetsc3.7.4 or libpetsc3.7.5. I had opened #851735 to binNMU dolfin, but closed it for this reason. petsc 3.7.5+dfsg1-2 (and slepc 3.7.3+dfsg1-4) should be fit for stretch once the 10 day migration period is done. Drew