Since Neos is PHP/web based, I guess it wouldn't be too time consuming to actually implement multiuser capability and make online wallet a possible option.
Online vs. privately-hosted wallets, it's all about the crew, right now Neos is more geeky oriented:
- advanced users love to have control of their installation and backups.
- regular crowd doesn't like or is unable to care about apache/php installation or regular backups, they want to be able to access their funds from wherever they want.
I think it's good to cover both types...