I don't know how to post links but if you go to thefuzz4.net then go to phones then Eris a how to roll back to 1.5 will pop up. But it only works if you rooted not for the guys who downloaded the leak.
Full Downgrade from Droid Eris 2.1 Root (any) to 1.5 Stock | The Android Mobile OS
this is the site i found