It would be nice if they had a comparison document detailing the differences between the Cloud Servers and their Slicehost service. I currently have a handful of slices, all of which might benefit from these offerings. However, I know with the Slicehost offerings I have persistent storage, bandwidth, etc. However, I don't normally use all my bandwidth or storage.
It would also be nice to know if they have any details regarding whether this will be integrated into Slicehost's Control Panel, or products, to allow easier migration, scaling, etc.
Well, I think the idea is that those details are coming on monday. But there are some details that we can know now since Cloud Servers is mostly just Slicehost combined with Mosso/Rackspace's support/billing channels. So, they'll be Xen instances with persistent storage. Right now the bandwidth question is up in the air since the site doesn't specify. Given the pricing, I'd have to assume some bandwidth would be included. At $700, their 15.5GB server wouldn't look so nice against an $800 slice that came with 2,000GB of bandwidth (which would cost $400 at $0.20/GB).
They'll probably be integrating this with the Mosso control panel.
EDIT: So, talking with the Mosso support, bandwidth is not included and it will cost 22cents outgoing. Makes the pricing look a lot less appealing against Amazon's EC2 - especially since Slicehost's previous key (persistent storage) is negated by EBS.
Mosso's live help is answering any questions you have and they seem decently knowledgeable. The information doesn't seem to be embargoed at all by Rackspace.
It would also be nice to know if they have any details regarding whether this will be integrated into Slicehost's Control Panel, or products, to allow easier migration, scaling, etc.