According to the analyst on BBC World Service earlier today, banks and building societies are not expected to cut their rates to borrowers.
The view of the experts seems to be that, because of the effects of the sub-prime credit crisis, lenders need to build up their capital reserves. To do this they'll probably be looking at increasing their interest rates, rather than lowering them. All that the 0.25% base rate cut will do is to slightly lessen the increased lending rates which are probably in the pipeline.
Chris