doesn't more address space just give us more routes to handle?
No. It only makes more possible prefixes. Migrating to IPv6 while keeping the current (IPv4) routing and current business relations, there would be somewhat less routes:
bigger address space -> bigger chunks -> less need to incrementally add prefixes to the same place -> less prefixes
You mean "more address space" -> "individual businesses want to multihome and are willing to pay for their own space" -> more prefixes. Every business that wants to multihome and can afford it already does. v6 isn't going to change that. v6 will allow more aggregation and a routing
table closer in size to the number of AS's, which is a significant reduction. It should also reduce the problem of route churn and non-convergence. Whether everyone will play nicely and make it work is a different story. -Don