The SCAR is apparently going to be fielded at some point.
I guess the OICW with the programmable-fuze 20mm cannon strapped on top of a 5.56 rifle is still being worked on. It has been in the works for 10 years at least... Maybe some day a ground-pounder will actually get the chance to haul it around.
But the G36? I have not heard anything about that.