Best guess I have seen so far is 1759 .uk per day (after the initial pre-registration calm down) posted on another forum, from somebody how knows there numbers.
Just to put that in some sort of context, that would be approx. 2,000,000 registrations in 5 years at that pace. Remember, we're only 24 days into a 5 year process. In marathon terms, we've not yet finished the opening lap out of the stadium...
Of course, there are a number of things holding back registrations at the moment (factors which may improve in future):
A) Nominet's not mailed existing registrants yet, so many/most will still be in the dark about .uk
B) Twitter doesn't resolve .uk domains as links
C) Chrome doesn't resolve .uk domains without "www." but turns them into searches
D) Nominet's ad campaign is more confusing than enlightening (lots of references to "LASER" and "SMS" and "SIM" and other things to try and conjure up the idea of "shorter" - but probably too subtle and too complicated for the low attention spans of today). That said, at least they are putting substantial marketing muscle behind it.
E) Some registrars and especially some hosting companies still don't support .uk correctly
F) No major sites are using .uk yet
G) Domain investors aren't likely to duplicate the bulk of their portfolios until they absolutely have to
H) Five years feels like "a long time" so there's no particular sense of urgency after the "keenest" people got their pre-registrations out of the way on day 1 of launch.
I) There has been very very little time for new .uk users to start publicising their web addresses (by definition, 24 days minus however long it took them to register their .uk after Launch Day)
I think it's fair to expect that some/most of the above will get better with time. Your guess is as good as mine as to exactly how much time each factor will take (they're generally not black/white anyway, apart from the buggy Twitter and Chrome behaviour)
