You don't need to remove the battery before following the directions on the wiki. All this will do is force a reboot before you plugin in the sansa, something you could do with the power button.
I imagine from your viewpoint what I'm suggesting is no more helpful than wrapping the player in tinfoil could conceivably be, so if your learned perspective is that removing the battery was completely superfluous, then I'll abate. I documented my attempts to resurrect the device, though, and I'd be obliged if you could look over my notes and offer a theory on where the process fell through; any correction you can offer can only help if it bricks in my pocket again.
The player, in it's bricked state, was displaying evidence of powering on and off; from an inactive state, the power button could be depressed and the blue ring would light up indefinitely; the longevity of this state was tested at one point by leaving it on overnight, and it was still lit in the morning. To make it appear to turn off, the power button could be held down for a dozen seconds or so, which would cause the blue light to turn off. Plugging the device in would turn it on but otherwise showed no effect on the player's behavior. The host computer (XP) never recognized it.
I started with the unbricking process by following it as literally as possible, at first. The process never explicitly mentions starting with the player plugged into the host computer, so I didn't; I effected the state in which the player appeared to be off, moved the switch to the Hold position, held down the Record button, and pressed the power button. The ring would light up, nothing else.
The same process repeated with the player plugged in did the same. The computer still failed to recognize the player.
Now believing that I was doing something fundimentally wrong, I rechecked myself; made sure the depression on the Record button was full enough to register, made sure the Hold switch was fully pushed to the correct position (tried both the orange and white positions), and also handed it off to another person and asked them to follow the instructions while I watched and said nothing. Their approach was similar to mine and also affected nothing.
Now finally wondering if perhaps there was a simple hardware problem (such as the Hold switch not being correctly attached), I opened the case. The battery, naturally, was easily removable, and without any direction in mind, I retried the process without the battery in the player. Of course I started with the player plugged into the host computer; the ring lit up, so I held the power button to return it to the off state, then began the unbrick boot. Switch to the Hold position, hold down the Record button, press the Power button...
Success. Of course. Otherwise we wouldn't be entertaining these silly notions. The player started, the Sansa boot-screen flashed for a moment before Rockbox initialized and displayed words indicating that it had entered Recovery mode, and the host computer immediately recognized the 16mb drive. The problem resolved from this point forward in a predictable fashion.
So what's the word? I don't pretend to have any theory about why this should have
technically worked (is black magic considered a technical resolution?), but I'll take it.
In any case, my player works; at this juncture I'd just like to know if my chronicle isn't useful to someone.
EDIT: Again, this is another thing I noticed that may have an excellent reason for leaving well enough alone, but wouldn't it be most expedient to suggest on the Unbrick page to attain a fresh .mi4 file directly from the latest Sansa patch than it is to direct them to Daniel's page?