I wouldn't have a clue where we are now. I believe that the questions concerning matter accelerating to the speed of light are completely irrelevant given Einstein's assertion on the amount of energy it would take to do this. Light is not matter... it should simply be seen as energy. If we could find out how space is actually structured, then maybe we could find out why the speed of light is 300,000 m/s. I have a few hair-brained ideas on this but nothing solid.
I also don't think that the curvature of space dictates gravity, as general relativity asserts. However, the bending of light near gravitational objects seems to suggest that matter does curve space to a certain extent, but until we can find out exactly what is being curved (a bundle of planck-lengths???), theories on why light travels at a particular speed will only ever be conjectural. We should all stop theorising on what light is, and focus more on the medium through which it travels (i.e. space).... i think this will give us more answers.
DG
