The argument for Chromebooks for many consumers is easy. I just look at my Mom and its easy to see the value.
I have been using a Google Chromebook at work for a little while now and I am starting to see the value to business users too. I have seen that enterprises will be able to lease Chromebooks for $28 a month per user. With enterprise apps moving to the cloud and the ability for many workers to do their job via a browser it has all the features required for most employees. Especially with what I have read about the coming partnerships with VMware and Citrix. The OS is so simplified end users don't see anything except the browser interface. And with everything in the cloud, no backups are required. Add in no viruses and no known malware on top of that. Then you throw in the management tools available to organizations this could be a great solution for many. Talk about a great TCO over MS Windows PCs and possibly even over Macs (especially now since Macs are being targeted with malware)!
An added point I noticed yesterday – once you put a full wrap around leather case on an iPad 2 there isn't much size nor weight difference between a Chromebook and an iPad. The interface (and maybe the targeted use) is totally different of course, but size and weight really isn't that different honestly.
Employees will just have to get over the fact there is no local storage. This was my biggest hang up for the first week or so…