Looking into it as we speak, but my computer crashed while playing this morning and as a result, when I logged in after restarting world 1 was no longer saved.
Basically - from what I've read online, I can just load a "new' file in the same slot and it will spawn me in my world, just at a different point. I went into C:\Users\Administrator\AppData\.minecraft\saves and backed up my world data, just in case. Ideally I would only have to repair the level.dat file in there, but because I crashed and got a BSOD while playing, the level.dat file was not merely corrupted, but missing entirely.
So after loading into my world, but at a different point, I made my way back to my original spawn. Utilizing a hex editor called NBTedit, I was able to reset my spawn point, as well as restore my inventory. Granted the latter was a painstakingly annoying process... changing dec values from dirt to pickaxes 16 or so times was rather cumbersome, but worth it.
Never fear, my world was safe. I am keeping a backup now not only on one of my external HDDs, but in my dropbox as well, juuuust in case.
Gunna do some mining tonight, hopefully will have another nice update on my 15x15 shaft later for you all ;)