There are still several questions yet to be answered, including how Google will account for sites in other countries that only want to rank on their country’s version of Google and which may have slower load times in the U.S. Several users have complained that it is Google’s tools themselves (such as Google Analytics and Google AdSense) that slow their sites down, and they wonder whether having these Google features will end up penalizing their sites.

The truth lies somewhere between “We’re doomed” and “Hallelujah!” Google’s Matt Cutts says that fewer than 1% of sites will be affected by this new development. If you go to code.google.com, you can find several boots-on-the-ground ways of speeding up your site, all of which are Google approved.

Personalized search also works on a broader basis when nobody is signed in. With web search history enabled even when nobody is signed in to Google, the search engine will generate results based on 180 days worth of web history, regardless of who went where on the web. And with signed-out personalized search, the individual sites that influenced the personalization can’t be listed, so even a fairly nosy person can’t deduce much from it.

Webmasters wonder whether personalized search will doom their SEO efforts or actually help them. For those who avoid any and all deceptive practices and who concentrate not just on keywords, tags, and all the minutiae of SEO but on providing top quality content, then personalized search will only help, because it will boost a site based on people reaching it and bookmarking it (or visiting it frequently), regardless of how they found the site.