If they were sold through LBS at a big premium to the BikesDirect price then that would be a dilution to the brand. As they are sold at the same price it just gives you a choice of where to source -I bought my CC w/o riding largely on its reputation.

Brand dilution would require same bike at variety of pricepoints or a cut-rate inferior bike badged as a Surly sold through a discounter - neither of these is happening.