But honestly, who has a server on 8.10? I'd say you're an extreme minority - and honestly Ubuntu provided plenty of opportunity to upgrade.
Ironically, if you were on the older version (8.04 LTS) you would've been able to go straight to 10.04 LTS. I would recommend this in the future, on server platforms staying with LTS releases, unless you want to upgrade every 6 months - which it seems like you do not want considering you were still on 8.10 .
This is the "recommended" method. Either stick to LTS and upgrade every 2 years, or if you want to stay on regular releases, make sure you upgrade every 6 months or so. Otherwise, you'll fall behind and run into another issue like this.
Microsoft doesn't have to keep up repo's like Ubuntu does, and I understand why Ubuntu does it the way that they do - they can't possibly support all the newer versions, and all the older versions, there's just too many. You just got caught out, like I said stick to LTS and make sure you upgrade before support has expired!