A takeover by Lufty now seems inevitable.
And, whether or not it buys the SAS stake, between Dec 2008 and June 2009 LH has a 'call' option over Sir MB's shares - in other words, LH can force Bishop to sell. It is difficult to see how LH will be able to resist a chance to get 11% of LHR's slots.
The end of Diamond Club and 'cash and miles' is therefore likely to happen within 30 months. Given the poor value offered by the LH programme, it would make sense to move towards burning rather than earning in 2008.
It may also be worth trying to get BMI Gold status in 2008/9, since LH would match that with a LH SEN card which would be valid for 2-3 years, depending on when in the year it is issued.