The Associated Press, which in its 2010 Stylebook went from Web site (two words, capitalized) to website (one word, lower case) while retaining the capital letter for the Web (not a synonym for Internet, by the way) announced more switches in AP Style at the February 2011 Phoenix conference of the American Copy Editors Society. The latest changes include “email” instead of “e-mail,” “cellphone” instead of “cell phone” and “smartphone” instead of “smart phone.” This works fine, of course, until auto-hyphen programs break these words between syllables and insert a hyphen at the end of a line.
Style rule changes can be seen as necessary to keep up with rapidly changing times and conventions–or as a way to make editors keep buying a new AP Stylebook every year.
My advice: Choose your own style rules. Then hire an editor to make sure you stick with them.