I have a blog for 1 year, and months ago, i change url name. From page rank 2, back to 0. Now, I do regret changing the name
In the eyes of spiders you have to deal with all the scratch ... May be you can build up your links by emailing those having your links so that You can get PR update quickly but still you will have to go from Scratch...
Did you change the actual url or just the name of the site. If you changed url you should have reidrected it to new one. You now have to get all the links you had before to list your new url. If you just changed name not actual url site will come back to old Pr. If you get same links to new url site will get same pr after update.
of course changing url will effect the page rank and serp because you will loose some of your backlinks when you do that
Do a 301 redirect from the old domain to the new domain if you can, and then try to get people linking to the old site to change their links to the new URL. Even with the redirect though, it can take Google a few weeks to transfer the PR from the old domain to the new one.
of course it changes. the PR isnt based on the content thats on your site. its based on the domain name, the content does help in determining the page rank but the ultimate fact is PR is for domains, not content
Exactly what I was going to say, do a 301 redirect via your htaccess file and then your PR should shift on to your new website. But I wouldn't fret about PR at all, especially with PR as low as PR2. Here is a link to help you do this: http://www.webweaver.nu/html-tips/web-redirection.shtml.