Should I use both WCF and ASP.NET Web API

Question

We already have a WCF API with basichttpbinding. Some of the calls have complex objects in both the response and request.

We need to add RESTful abilities to the API. at first I tried adding a webHttp endpoint, but I got

At most one body parameter can be serialized without wrapper elements

If I made it Wrapped it wasn't pure as I need it to be.

I got to read this, and this (which states "ASP.NET Web API is the new way to build RESTful service on .NET").

So my question is, should I make 2 APIs(2 different projects)? one for SOAP with WCF and one RESTful with ASP.NET Web API? is there anything wrong architecturally speaking with this approach?