That's correct, I dropped my Streak down to FroYo, downlaoded your .zip, extracted them to a folder, booted into Fastboot, ran "fastboot flash system system.img -w" and "fastboot flash boot boot.img -w" and I'm stuck at the Dell logo on the first boot. I know that after flashing you can wait for the first boot for a while, so I left it for an hour and no go...That is the best place.
So you downloaded the zip file in my OP, extract its contents, and flashed those? I want to make sure we are on the same page.
Some people are getting confused in thinking this is a flashable zip that you would do in CWR, which it is not.
I FINALLY got the Honeycomb update.pkg to download so I'll try running that from the stock recovery and give your boot/system.img another try after that.