Since much of the banking world is heavy users of WCF, Microsoft has no other option that to implement WCF in. Net 5 unless they want to loose the banking industry. I did come across a post from one of the WCF products managers who said that they are working on a cross platform solution but it will take some (much) time before that has been completed. Cannot find this post, but I consider it safe to say that WCF for .net 5 is coming and that I am stuck util it does as there really is no alternative to using WCF
