I agree with Equity & Local on this. .co.uk has alot of value for UK based business - I certainly see it advertised (on billboards, trucks, newspapers, etc) more than other extensions, except for .com, and even some days I'll see more .co.uk than .com
If you plan on developing, then I would grab both .tv and .co.uk if you can. Heck, Kent (a county in Southeast England for those that don't know) is launching an online tv channel in the near future, and since they couldn't get kent.tv (a developed Japanese site) they're launching with KentTV.co.uk