1) No matter how you decide this for the server-side, you can easily consume Webservices and WCF Services using only WCF on the client-side. This is of value, if you consume multiple services with a single client.
2) If you consider Cloud Computing: It is possible to host WCF Services on Windows Azure.
* Only the classes which implement IEnumerable interface.
* Classes that implement the IDictionary interface, such as Hash table can not be serialized.
Important difference between DataContractSerializer and XMLSerializer:
Quick benefits of WCF over Web-Services (ASMX):