A Verizon spokesperson recently confirmed to ComputerWorld that the Droid Eris will not be receiving any further Android updates and will not be updated to Android 2.2, Froyo. The Eris is nearly identical to the Sprint Hero, which also will not be updated past 2.1, Eclair.
The news that the Eris (and Hero) won't be receiving Froyo updates is disappointing, but sadly, not surprising. Froyo runs just fine on old hardware, as root users will tell you. Even the G1 and original MyTouch are perfectly capable of running Froyo, so it's sad that Eris and Hero users won't get official updates.