I honestly believe its going to takes years (5, maybe even 10) before .UK is considered a first choice for end users because the general public is just too familiar with .co.uk, i happened to speak to someone this week outside of domaining who had bought a .UK from someone like godaddy.. so i asked what made him buy the .uk... his response was... "The .co.uk was taken and the .UK was cheaper than any of the others" so maybe this will be a slow process and the general public will start to walk towards the .UK based on most .co.uk's being taken, however, i expect that to take a considerable amount of time.
Furthermore, from an investment stand point its the perfect "Buyers" market at the moment due to no competition and very little spending so outside of being willing to sit on a .uk domain for the foreseeable future and strictly for investment purposes then i see no .UK sales making the headlines anytime soon unless you get the odd "Big Brand" buying one for future use but given the current financial situation world wide i think that is a long shot too.