Our analysis shows that for the most popular 500 sites, JavaScript is used in 93%, Flash in 27% and about one-third (30%) use XMLHttpRequest, a technology used to generate dynamic updates. Uptake of XMLHttpRequest is approximately 2.3% per year across a random selection of 500 sites and is probably higher in the most popular sites. So, when examining dynamic updates from the perspective of visually disabled users, evidence suggests that, at best, most users can currently reach updated content, but they must do so manually, and are rarely given any automated indication that any update has occurred. With technologies enabling dynamic updating of content currently deployed in about 30% of the most popular sites, and increasing annually, action is urgently required if visually disabled users are to be able to use the Web.