Question: When I expose a service using NetTcpBinding, is .Net remoting used under the surface? Could I consume this service using .Net remoting on the client side?

I ask this because I always thought that WCF was just a wrapper for underlying protocols such as WS\*, Remoting, COM+, and MSMQ. And while I know that exposing WS\* will work as expected, the others seem to be more ambivalent.

Answer: 
WCF is more than "just" a wrapper. It's a pseudo-magic layer that handles a ton of stuff for component developers according to configuration information. With WCF you can create a service contract and an implementation and then use them across multiple machines via HTTP, HTTPS, NET-TCP, on a single machine via named pipes, securely, non-securely, etc etc all just by adjusting configuration settings.

This is way, way different from what .net remoting does.

Grab a copy of "[Programming WCF Services](http://oreilly.com/catalog/9780596521301/index.html)" by Juval Lowy to get a better feeling for what all you can do with WCF.
WCF/NetTcpBinding is not the same as remoting. WCF is a message-based API; remoting is an activation/proxy framework (essentially) ([see also](http://msdn.microsoft.com/en-us/library/aa730857(VS.80).aspx)).

I very much doubt you could consume a WCF/NetTcpBinding service via a remoting client; they are just too different.

WCF is a framework that provides unified access to a number of messaging protocols - and indeed you can add your own - but it wouldn't be easy.

I suggest using a proper WCF client, or (if this isn't possible) use a basic-http client, or (my least preferred option) old-style remoting if you really, really must.