I was worried, too, and then saw and ordered a little gadget for my Captivate, just in case. Normally, with the Captivate, there is a way to get a bricked phone into download mode (a developer mode of sorts that you can use to load stuff onto it) by inserting some wires or something into the USB/power port in a particular way. Somebody sells a little plug that automates that, so I bought it for about $10 just in case I needed it (I didn’t need it in the end).

It was time consuming, but not overly difficult. The only part that had me sweating was when I couldn’t get ODIN to recognize my phone. ODIN is the program to restore a phone back to stock status, which is the starting point in the instructions mentioned in the post. By then, my phone was already in a non-usable state, so I was a bit worried. I finally re-downloaded ODIN from another site and put it on another machine, and it worked from there.