I am only using this blog to post technical articles but that one is too much interesting.
Astoria, officially named as "ADO.NET Data Services framework" is the kind of product that I love. It's using the best APIs we have today to build something useful, powerful and simple at the same time !
You can expose any Linq source (IQueryable) through Http using a WCF service.
Thanks to .Net 3.5 new WCF features, Astoria is using the HTTP/REST api to define the equivalent of a Linq expression.
On the client side, you can use any httpclient technology to send requests.
You can ask WCF to format the data using JSON instead of SOAP.
My favorite one is, if your client side is a rich application (.Net based, like Silverlight 2.0, WPF, Winforms), you have a proxy generator tool (comparable to 'Add Service') that proxies all your entities in a client side data context, implementing the Linq technology locally. This means that you can define remote linq queries on the client side and execute them on the server without dealing with any communication technology.
I also see in Astoria a symbol of the Linq generalization of everything that touches data in the .Net world and that is really great.