At the 2007 Search Summit – The Australian Search Marketing Conference, Aaron D'Souza, Software Engineer, Google Search Quality alongwith co-workers, Maile, Peeyush, Dan, Ada hopped from the US Google offices to share, discuss and learn topics that are dear to Webmasters/SEOs/SEMs/users and their like.
As soon as webmasters voiced concerns about whether personalized search would affect the Webmasters, the team responded with "a resounding NO! For the webmaster, it allows niche markets that collide on the same search terms to disambiguate themselves based on individual user preferences, and this really presents a tremendous opportunity for visibility. Also, to put things in perspective, search engines have been moving towards some degree of personalization for years; for example, providing country/language specific results is already a form of personalization, just at a coarser granularity. Making it more fine-grained is the logical next step, and helps level the playing field for smaller niche websites which now have a chance to rank well for users that want their content the most."
When Webmasters asked the reps about moving from one domain to the other while also taking along your credibility, the reps answered.
" For each page on domain X, have it 301-redirect to the corresponding page on Y. (How? Typically through .htaccess, but check with your hosting provider).
You might want to stagger the move, and redirect sub-sections of your site over time. This gives you the chance to keep an eye on the effects, and also gives search engines' crawl/indexing pipelines time to cover the space of redirected URLs.
http://www.google.com/webmasters is your friend. Keep an eye on it during the transition to make sure that the redirects are having the effect you want.
Give it time. How quickly the transition is reflected in the results depends on how quickly we recrawl your site and see those redirects, which depends on a lot of factors including the current reputation of your site's pages.
-Don't forget to update your Sitemap. (You are using Sitemaps, aren't you?)
-If possible, don't substantially change the content of your pages at the same time you make the move. Otherwise, it will be difficult to tell if ranking changes are due to the change of content or incorrectly implemented redirects."