HTC’s support site recently announced a fresh OTA (Over The Air) update for HTC Hero, that some claim to be Android 2.1. Things certainly don’t look like it, since this is a “Firmware over-the-air (FOTA) client update & YouTube player Update.”
The device gets updated to “2.73.405” firmware and you can get the upgrade by visiting the “Updates” section on HTC Hero. Some news sites and users have called this the Android 2.1 update, but this has yet to be confirmed officially. Have you tried it yet?