the dietary and other laws proscribed in leviticus were ways the jews sustained their newly formed society.  dietary to prevent disease, not mixing wool and cotton to create a superior piece of clothing.  following these laws assists me in my kavenah about being jewish.  you're not going to go to hell, or banished from the community or stoned to death for mixing meat and dairy, wool and cotton, but not doing it may make you forget the symbolisim behind it - sustainability of the jewish society. 

 i do understand that there are many ways that we do sustain our society and community, especially those of us living in the diaspora, but we have to be careful not to confuse enhancement of tradition to reflect the world we live in, and assimilation.