before you do anything drastic,let's try some thing.
There should be a PMU reset sequence for that machine. It is either a combination of keys or a reset button on the back. I'm leaning toward the reset button.
Whichever it is, do it.
Try the reboot. If it fails:
1. Remove the battery and try the boot using just the AC adapter. If it books correctly, you "may" have a defective battery. Repeat with battery In.
2. Use the OS installation disk to see if the machine will boot from it. It it does, and you still cannot get the machine past the progress bar, you may have to go for an Archive and Install of the OS. Something go corrupted during the discharge.
You "may" have annoyed the Power Management Unit (PMU) during this total discharge

P