I find that is a pain; in that I have .NET at both ends, have the same "contract" dlls loaded at both ends etc. But then I have to mess about with a lot of details like "KnownType" attributes.
WCF also defaults to only letting 1 or 2 clients connect to a service until you change lots of configuration. Changing the config from code is not easy, shipping lots of comfig files is not an option, as it is too hard to merge our changes into any changes a customer may have made at the time of an upgrade (also we don't want customers playing with WCF settings!)
.NET remoting tended to just work most of the time.
I think trying to pretend that .NET to .NET object based communications is the same as sending bit so of Text (xml) to an unknown system, was a step too far.
(The few times we have used WCF to talk to a Java system, we found that the XSD that the java system gave out did not match what XML it wanted anyway, so had to hand-code a lot of the XML mappings.)
