I emailed HTC Support & asked them if the Eris is going to get the 2.1 update and when. Below is the answer I got. 
New Response From [ Alvin (North America Support (Tech)) ]
Hello Dana,
Thank you for taking the time to contact HTC America Technical Support via E-Mail with your inquiry about when the Verizon Wireless DROID ERIS by HTC will receive an update to Android 2.1 (?clair). My name is A.J. and I will be happy to assist you today.
I understand how important it is for you to have all of the available information about upcoming software updates for your device. Verizon Wireless has confirmed that the Verizon Wireless DROID ERIS by HTC will receive the Android 2.1 (?clair) update. The Update will be available within the first six months of this year, very possibly within the next few weeks. The release date is dependant upon carrier testing and certification. The Update will be pushed OTA (Over The Air) by Verizon Wireless, OTA updates can take time to be pushed to each individual device so even once the update is released it may be a few days before you see a notification on your device.
Dana, if you have any future questions about your device please feel free to visit HTC - Mobile Phones, Smartphones, Cell Phones, PDAs and send us another e-mail. You may also enjoy community.htc.com, our customer-based community, which has a myriad of information on HTC devices. You can also follow HTC on Twitter at HTC (htc) on Twitter, you can become a fan on Facebook here HTC | Facebook, and you can watch videos of new HTC products on Youtube at YouTube - HTC's Channel. I would also like to invite you to participate in a customer satisfaction survey located at HTC Online Survey. I hope you have a great day and thank you for choosing HTC!
HTC America
Technical Support Representative,
A.J.
CountryUnited States
Inquiry Information
Inquiry TypeTechnical Support
Inquiry DescriptionDo you have any idea if the Droid Eris will receive the 2.1 software update and when? Thanks, Dana
Issue Date & Time
2010/03/05 01:34

New Response From [ Alvin (North America Support (Tech)) ]
Hello Dana,
Thank you for taking the time to contact HTC America Technical Support via E-Mail with your inquiry about when the Verizon Wireless DROID ERIS by HTC will receive an update to Android 2.1 (?clair). My name is A.J. and I will be happy to assist you today.
I understand how important it is for you to have all of the available information about upcoming software updates for your device. Verizon Wireless has confirmed that the Verizon Wireless DROID ERIS by HTC will receive the Android 2.1 (?clair) update. The Update will be available within the first six months of this year, very possibly within the next few weeks. The release date is dependant upon carrier testing and certification. The Update will be pushed OTA (Over The Air) by Verizon Wireless, OTA updates can take time to be pushed to each individual device so even once the update is released it may be a few days before you see a notification on your device.
Dana, if you have any future questions about your device please feel free to visit HTC - Mobile Phones, Smartphones, Cell Phones, PDAs and send us another e-mail. You may also enjoy community.htc.com, our customer-based community, which has a myriad of information on HTC devices. You can also follow HTC on Twitter at HTC (htc) on Twitter, you can become a fan on Facebook here HTC | Facebook, and you can watch videos of new HTC products on Youtube at YouTube - HTC's Channel. I would also like to invite you to participate in a customer satisfaction survey located at HTC Online Survey. I hope you have a great day and thank you for choosing HTC!
HTC America
Technical Support Representative,
A.J.
CountryUnited States
Inquiry Information
Inquiry TypeTechnical Support
Inquiry DescriptionDo you have any idea if the Droid Eris will receive the 2.1 software update and when? Thanks, Dana
Issue Date & Time
2010/03/05 01:34