To be released on August 19, 2014.
Taylor's been having radio DJs and heads over to her apartment in NYC for exclusive listening parties to the new single. One of them tweeted the following:
https://twitter.com/djdan1033/status/497560006804668416

Tune into Taylor's worldwide livestream with Yahoo! Screen on August 18, 2014 at 4pm EST for the beginning of LP5!

OH MY GOD

SLAY TAY

yas taylor slay

First page before the lock

Cant wait to hear it

The title sounds really intriguing!

no 1 cares, shes a bitch

Becky. Look at her butt. It is so big.

The title tho

Is this one of the Max Martin tracks?

Omggggg

omggg I use already

Title is speculation and both title and release date aren't confirmed.

Edit: If the title and release date are both confirmed then this can be reopened.