Just tried messing with the bootloader, but with some problems: (I rather to see a problem first than to have them later!)
Here's what I did earlier:
1.) Created a SD card with Linux from R-pi tutorial.
2.) Accessing the boot partition - replaced the "kernel.img" with the "kernel.img" from dwelch67's webpage (bootloader05).
3.) Connected the serial port to the R-pi (checked the GPIOs), using a Prop-plug (Parallax Inc. - they used the same USB->Serial converter) They are 3.3V compatible, so there wouldn't be any cooking occuring there.
4.) Used a Realterm because I do not have a Linux to do the "minicom" thing. I dumped the "blinker.bin" and unfortunately I didn't see anything. Should there be a feedback from the R-Pi to the terminal saying that "R-pi Bootloader is connected"?
5.) From the dwelch67's tutorial on the newer B+, where's the GPIO47? I think the problem in (4) is because the particular GPIO is sharing with the RX pin. (I have the Raspberry Pi A+).
I'll keep reading for more info - most of the tools are geared towards Linux and since I'm a long time Windows user, I have to do it real slow.