I picked my domain name when I really didn't know what my site was going to be about. Now in retrospect I chose a domain name that's not very memorable and completely unrelated to my niche. I get most of my hits from Google and I'm wondering if there is any way to move my site to another domain and have Google replace my new site with my old one in the SERPS. Is there anything google does that allows sites to move to another domain and carry over all the back link credit from their old domain?
My answer : NO. Google will not help in shifting domains and carry forward backlinks or pr. You have to do it yourself and contact those webmasters that had you links to change it. Because eventually your links reside on other websites. Using 301 redirect will only index your new website quicker and it is useful in telling Google you have moved. It till take weeks to months depending on how frequent Google visit your old site.
best thing you can do in this kinda situation is to use redirect. that way when google visits your existing site, it will redirect google bot to your new site and get indexed. also currnet site will pass some PR to the new site as well. but there is no way to carry over all the backlinks to the new domain. so do a redirect, and keep building links for the new domain