The bulbs to look out for are the new LED ones - still horribly expensive and fairly 'first generation' according to the man in john lewis bulb department yesterday (when I was trying to buy a low energy light bulb for a kitchen spotlight).
They only carry a few, having looked on the internet there seem to be a bigger range and cheaper than John Lewis. JL are charging about £20 a bulb, online there seem to be some for about £10, no idea of relative quality. Have also spotted them being used in my local homebase quite a few of their demo lights, no idea what their prices are. One thing that was noticeable though was that the temperature of the lighting display area (usually warm from all the lights on!) was much cooler than usual.
But - JL ones at least - have a lifetime expectancy of 50,000 hours (he reckoned about 40 years), they are instantly bright, they are a better tone of white light than they used to be, they are much more energy efficient - along the lines of they only use 10% of the power of a bulb (I think an energy saving one but not sure) so should save at least £10/year per bulb in electricity. Also no mercury, lots less heat generated, much more robust, and lots of other advantages that I have forgotten now. Unfortunately not yet dimmable but as this is still early days for them, hopefully they are undergoing lots of development and they will be getting brighter and dimmable and cheaper!
anyhow, might be worth keeping a look out for them... not sure if there is anybody else out there who knows any more about them, I don't know much!