'Leapfrog' is reported to have lost its hyphen, and rightly so I should think. It is a specific kind of motion. A 'leap-frog' should refer to a kind of frog, don't you think? Don't even think about 'leap frog' -- sounds too close to a leap year.
According to the story, the sixth edition of the Shorter Oxford English Dictionary has knocked the hyphens out of 16,000 words. 'Fig-leaf is now fig leaf, pot-belly is now pot belly, (and) pigeon-hole has finally achieved one word status as pigeonhole'.
I never did like the hyphen much, probably because I could never use then properly. It looked very tentative and it looked as if I was using it because I was not sure. That was true. Most of the time I was no sure. (Not as bad as the semicolon, but close -- is that word hyphenated too?)
Coming back to the article though, I cannot understand why some articles should be divorced and forced to become two words. We all know what a 'testtube' is, but why should it become 'test tube'. We know exactly what it refers to. Is it because the closeness of the two 't's in the middle makes the eyes go wonky? "Get away from there you two! You are getting too close, and in public too."
Apparently, all this can be blamed on electronic communication ... 'we no longer have time to reach over to the hyphen key.' (!!!) And since English doesn’t have a central governing body (not there are no, self appointed, language Nazis), anything goes.
But even I have to admit that the hyphen cannot be entirely done away with. Whether it is 'e-mail' or 'email' is a quibble. They both mean the same thing and the latter is easier to write. But a 'walking stick' and a 'walking-stick' are quite different. If you come across the former: run.
Full story: http://news.bbc.co.uk/2/hi/uk_news/magazine/7004661.stm