You'll note the speaker is a woman, unusual for videos like this from Syria, and the man stood second from the left is the notorious Abu Sakkar. This isn't the first video Abu Sakkar has appeared in from Qusayr in recent days, with this one showing him wearing a red shirt. Here's what's said (thanks to @rtoufic)
Woman - We will purify Qusayr from the Lebansee HezboLLATE (Devil's party) and we won't let Qusayre be easily swallowed by Hassan NarsouLLATE (Supporter of the Devil). Those of them who want to be grieved by their mothers, and see their sons buried, and their wives widowed, or their parents grieved, those will be ... (unclear) by the land of Syria and those who want to accelerate the process will be ... (unclear) by the land of Qusayr. Indeed, men and women we took up arms only to tear apart your bodies.
Abu Sakkar - We will prevail or die.
Off camera - Takbir.
All - Allah Akbar.
It's interesting to note in Abu Sakkar's statement to the media he made a similar statement "Victory or Death".
It's not possible to verify the date this video was filmed, but it is possible verify the location as Aisha Square. You'll note the lay out of the streets and buildings in the video match what's on the satellite map, in particular the location the the mosque's minaret on the northwest corner of the mosque. The camera position is directly west of the clock-tower, pointing east.
Today an image has been circulating showing what's supposedly the position of videos published in the last couple of days from state media and opposition sources.
If this image is accurate it would point to the southern half of Qusayr being under government control, or at least contested.