From a conversation with Brewster a few years ago: The doubling of density of disk drives has allowed them to stay relatively neutral with respect to space for the Wayback machine. It still occupies approximately the same size as it has for the last 10 years, which is essentially a set of racks about 15-20 feet long altogether I think?

However, the new TV news and search capability requires substantially more space than even the archive IIRC, or certainly is heading that way.