For Youtube Instant, the actual search terms are hitting suggestqueries.google.com for the autocompletion, which is what is powering google.com. The actual vid

For Youtube Instant, the actual search terms are hitting suggestqueries.google.com for the autocompletion, which is what is powering google.com. The actual video coming through is likely from a CDN, which are already built upon an infrastructure for scaling. Probably not as big of a deal as you think. Bandwidth wise it's unlikely that somebody watches the entire video as much as they rapidly hit different videos.