Matt Cutts, Google’s unofficial SEO spokesperson, recently has said that the time that it takes a website page to load in a browser is now an important factor in your Google ranking. So if your website has inline styling, is table-based, built around Flash or image-heavy, chances are that your page download times will hurt your sites ranking in Google. Now might be a good time to invest in a website upgrade to convert your site from old, tables-based HTML to a new, cleaner, and faster CSS-based site.
If Matt Cutts says it, time to do it.