Wash U took about 2-3 weeks, but I don't think you have to wait to be rejected from the combined program before getting an MD-only interview. I'm pretty sure someone on this forum went for the MD interview before hearing anything at all from the MSTP folks. In fact, that's how I thought it worked at most schools. Am I wrong about that? Am I going to wind up being rejected from some school's MSTP too late to be considered for the MD-only program?