You can argue it's a style issue. It does seem readable with just the one space though, or at least it is to me.
At work, most of my communication is via e-mail. The two spaces really stand out now, like they do in this paragraph. When I see an old e-mail or post of mine the two spaces seem just wrong.
But maybe switching to the single space is like wearing a toupee or dying your hair. You aint fooling anyone, you're still an old fart.