Transitioning to a next-generation internet could be akin to changing the engines on a moving airplane.
Routers and other networking devices likely will need replacing; personal computers could be in store for software upgrades. Headaches could arise, given that it won't be possible simply to shut down the entire network for maintenance, with companies, schools, and individuals depending on it every day.
And just think of the costs--potentially billions of dollars.
Advocates of a clean-slate internet--a restructuring of the underlying architecture to better handle security, mobility, and other emerging needs--agree that any transition will be difficult.
Consider that the groundwork for the IPv6...