You can not downgrade or root the leak. This downgrade is for people whom rooted from 1.5 to 2.1. Once you install the leak you can not do anything else except upgrade once an upgrade is available.
I know.. again. But again, that's today, tomorrow may be totally different with what a Dev discovers, no? Look at the leak, no root for what? a week? The theory stands till all the Devs say leaked will NEVER be rootable.
Either way, it's still useful info for some people..
Now back to figuring out WHY my phones won't register on Verizon.. their techie gave me all the codes and passwords to allow me access, I'll brick my wife's 1st then wait for their 48 hrs... ROFLMAO