I get the impression that one issue (if there is an issue) may be that people who try and fail to get the .uk may then try and type in the .uk to see what happens - but I'm sure most of us haven't doubled down on our portfolios so the answer is "nothing at all happens". And at that point the slightly interested, vaguely potential buyer gives up and looks for a different domain.
That said, it's only been 4 days. Too early to talk of trends.
Also, Nominet's not been doing much to alert the 10,000,000 existing registrants yet. Once they start getting clued in, they may well cast around for other domains at the same time as securing their .uk (well, it's at least the time they're most likely to be thinking about "domains" rather than just minding their existing businesses) so that may bring some expressions of interest.