Possible Duplicate:
SEO and multiple domains to same site
I have a domain I recently purchased. I went ahead and pointed it at my website(via DNS) and by default, my server now serves my website on this new domain. Eventually, the new domain will replace my old domain(with 302 redirects and all that). However, I've not yet got my website ready for that because I'll need to do some rebranding and such.
Am I actively hurting my SEO ratings and such by having these two domains point to the same thing?