Previously, Google required everyone to make a Google+ profile in order to get a new Gmail account. This made a lot of people very angry and has been widely regarded as a bad move. Now, that requirement has been lifted. Sort of.
While it was still technically possible to create a Google account without tying it into Google+, it was very difficult. Now, if you sign up for a Gmail account, you have the option of saying "No thanks" to a Google+ profile.
This doesn't come without some drawbacks, of course. You won't be able to leave restaurant reviews, rate apps or content on the Play Store, or (perhaps most frustratingly) comment on YouTube. However, if you'd prefer to stay out of the Google+ fray, it's now an option.
Mandatory Google+ Gmail Integration Quietly Shelved [WordStream via MakeUseOf]