You can definitely mix regular quilting fabric with batiks. I've been doing it for many years. Coincidentally, there was an article in a recent quilting magazine about "the new trend spotted at the October 2012 quilt shows of mixing batiks and non-batik fabrics."
Here is an example of one of my recent projects. A few of the orange and purple fabrics are batiks. A few fabrics are old fashioned calicoes.