Can you clarify what you want? Do you want SME to be hosted in the cloud as your own private cloud server? If so then yes. There are many cloud providers or IaaS (Infrastructure as a Service) providers who's job is to enable this. Amazon EC2 is an example. Many features on SME do assume they are on an internal network and in this case you would have to enable a VPN to access those features. Again most IaaS providers have a solution for this.
If your intent is to provide some other cloud services then the answer is maybe depending on what you want to do.
In either case above I'm not aware of anyone actually doing this with SME server but it is theoretically possible. Personally I have just not yet found pricing to be sufficiently compelling to take advantage of this (this will change with the hyper competition in this space) and in my case the data traffic in and out of my SME server to my local network is quite high.