You are talking about
A Song of Ice and Fire series by George R R Martin.
First a sport some love,
Though it drinks their blood.
Named for just a seat,
Though power is the key.
A Game of Thrones
Sport refers to the game in the title. In the game of thrones, you either win or you die, referring to the drinking of blood. The seat is the Iron Throne. And power is what everyone is vying for.
Then the sound of metal,
Slamming together in war.
That of which there are five,
Vying in the first name.
A Clash of Kings
Swords clash in this book, with the war of the five kings who want to lay claim to the Iron Throne.
A hurricane with thunder,
Lightning and pouring rain.
Weapons are out in the darkness,
Blades are bared to kill.
A Storm of Swords
Hurricane is a type of storm. Swords are the weapons.
A banquet is laid out,
Food for all to eat.
All, or just the birds?
Blackness on this day.
A Feast for Crows
A banquet is a feast, but this feast is for the crows only (resulting from the death of many in war).
Tango, hornpipe, rumba,
Ballet, waltz, and salsa.
Partners might be burnt:
Be careful how you step.
A Dance with Dragons
Careful how you step is a reference to dance in the title. Partners might be burnt might refer to the dragons in the title, or that fact that a couple of major characters meet their death by fire in the book.
As for the next two verses,
no one can speculate how the story may pan out, because GRR is a psychopath! But I'll take a stab at it anyway.
A white march to the south,
With the breeze bringing snow,
A life and death battle,
The unexpected end of many more.
A sweet end we hope,
The flowers bringing cheer,
A vision too bright,
In the rest of night.
Here are LogicianWithAHat's verses, which I feel are far more creative.
Howling from the north,
Before the year is done
The final season roars
A vicious zephyr
Asleep as new life grows
The song ends with a beginning
And though the night is long
We have visions of it ending
