Imagine you HAD to start a business on EITHER .co.uk or .uk, but couldn't own them both, which would you choose? For me, I don't think .uk replacing .co.uk is a foregone conclusion even if it's released. For example, .com.mx is still by far the most used extension in Mexico even though .mx was released 4 years ago. .mx still has less than 50% as many registrations as .com.mx. I'd assume that given the brand-awareness and marketing that .co.uk has had over .uk over the years, it would take at least 4-5 years for .uk to overtake .co.uk. After all, why would someone want to spend thousands developing a site on .uk when an older, more popular site already exists on .co.uk, and is by no guarantee going to replace it. For the everyday business, this probably means .co.uk is a smarter investment for the foreseeable future, as any business that wants to seriously invest and build upon a .uk will probably want to acquire the .co.uk anyway, rather then the other way around. Also makes me wonder if a .org.uk website would actually want to upgrade to .uk if it doesn't own the .co.uk.