Loved this first episode and I was genuinely freaked out several times. On my second viewing everything made a lot more sense and I can honestly say that it was ____ing brilliant! As for Moffat and company painting themselves into a corner, I highly doubt it. Even if the Doctor is dead, if Batman can return from the grave, I can guarantee a Time Lord can. It's all about what goes down with that Astronaut (and who was in that suit), those 200 years the Doctor spent running, Amy's pregnancy, and the final revelation about who or what River Song is. Within those four story elements right there is how the Doctor escapes from death. Hell, if Batman can plan ahead and escape the Omega effect and the living death that entails, the Doctor will be able to escape the grave as well. If you're wondering why I'm bringing up Batman, well that's what this entire situation reminds me of--Morrison's Batman RIP and the Return of Bruce Wayne. Just my two cents.