Well, unfortunately for me, that seems to be the new standard. Here's what Contrary says:
Use only one space between sentences. Only one space is needed between sentences unless you are using a typewriter. Typewriters are monospaced – they allot exactly the same amount of space for an i as for an m – and monospacing tends to visually obscure the transition from one sentence to the next. So for many years typing teachers have taught their students to use two spaces between sentences. But word processors, including the one you’re sitting at right now, are capable of proportional spacing – they allot about one-fifth as much space for an i as they do for an m – and a single space is sufficient to distinguish between sentences in a proportionally spaced document. Have a look at any professionally-produced book or magazine and you’ll usually find only one space between sentences.
Personally, I still prefer the look of two spaces -- despite all the single-spaced typesetting I read every day. Besides, I was taught way back when by none other than Miss Bernstein, my Junior High School typing teacher, to type two spaces -- and that's my reflex (even here, writing about it... although I see Blogger software automatically changes it to one space). But, if one space really is the standard, that means I'll have to change my reflexes -- and start changing work I send out.