We are in a season of Web Presence upgrades. For those operating self-hosted sites with WordPress.org, you should be aware of the recent release of the WordPress 4.0 site engine / CSS.
Matt Mullenweg <m@wordpress.org> circulated the following announcement the other day…
Just a few days ago, we released WordPress 4.0 “Benny” which has already been downloaded almost three-and-a-half million times! This release includes major improvements to the plugin directory, a much more pleasant environment to write in, with better embed support and an auto-expanding editor, and finally media has been made more functional and beautiful.
The reasons to upgrade are compelling … see those at the link above.
Anyway — if your upgrade means a complete web migration — you’re replacing a legacy site altogether — you’ll have issues with URL’s. Here are some things to note.
If you have analytics data you should use it to design page titles in your new site. If you don’t there are some other tools you can use that will help you anticipate the best keywords. (Ask us?)
Designing the page titles is important, but not critical — just realize that you can re-word these things as time passes.
But what about all of the existing SEO results that point to your old pages? In your new site you should be able to install what are known as URL redirects. These accept traffic from the old URL and “land” those visitors on the new page.
Be sure you have analytics operating in the new site. You’ll be able to see which URL’s are being visited, but importantly — you ‘ll also be able to identify old URL’s that you need to provide redirects for.
Designed Online Success 
Reblogged this on Anatomy of a Web Presence and commented:
If you don’t know how much site traffic you’re receiving, taking a month to measure it isn’t a bad idea before moving to a new “Web Presence.”