Not as bad as first suggested
As widely leaked, the actual proposals in the Budget today were not as draconian as initially proposed. Current situation is 'days of arrival and departure' do not count in adding up to the 90 day average over 4 years. So a Monday-Wednesday visit until April 5 2008 counts as one day.
As originally proposed in October 2007 they would have - a Monday - Wednesday visit would count as three days.
What is now proposed is 'midnights' count as a day's presence in the UK - so Monday - Wednesday is two days.
AND there is a transit exemption if you are 'in transit between two places outside the UK' - even if you are there at midnight it does not count UNLESS you do something not related to the transit - eg have a business meeting. Don't know how that will count for night stops.......
Source: HMRC Budget 2008 note 102