A lot of guff spoken above.
adamschic - don't forget that with the introduction of the Lib Dems policy of increasing the point at which one pays any tax at all, the higher rate taxpayer threshold has been brought down to ensure that higher rate taxpayers don't benefit from the changes. Plus over the years, the higher rate tax thresholds have not kept up with inflation ie those on relatively far lower salaries are now higher rate taxpayers, and this will become increasingly more so as the Lib Dems continue increasing the cut-off point when tax is paid at all to 10 or 12 grand (a worthy enterprise, but one with the side effect of ensuring that many more people are now higher-rate taxpayers, and that number will increase until HRT starts at 40K or lower).
What this means in practice is that - unlike many years ago when you were a higher rate taxpayer - it is no longer only the comfortably off who are higher rate taxpayers. 40K will not buy a life of comfort for a family in the SE - if that family has 3 kids, it can ill afford to lose £188/month - I know, because we are one.
For us - contrary to some bizarre claims above that it all goes on the 3rd games machine, or the 7th telly or something - that money is absolutely essential for food and basic essentials. (We have 1 telly and no games machines at all.) Our rent (we can't afford to buy) in the SE is v high; even with a long commute into London. Moving to a cheaper part of the UK is not an option - my OH's job can only be done in London. I do work part time as well (no way we could afford for me not to), but with kids full-time work would cost more than part-time, due to childcare costs).
So no, rest assured that whilst there may be some (increasingly few in this day and age) whose child benefit is saved up for a rainy day or spent on luxuries, there are plenty of families - including those with one HRT payer - for whom it really is an essential.