The story isn't over now that the credits have rolled.  There's more to tell, and the foundation was laid in a series of stories that turned out to be related.

UPDATED June 12, 2010, Yes, Virginia, there is an update, The Scent of Ancient Dust.  Xander's in Africa, and he's in trouble, and Spike and Ethan have been sent to help.

There's also a small story called Appointments (to be added in a bit)

Reflections in a Turning Mirror  How Giles escaped from the Bringer and how he got those papers from the Watchers

No Going Back--Rayne and Giles on the road to Shanghai, in search of the last Potential Slayer and what future the past may have

Sing Thee To Thy Rest  Vale, Cordela. AtS S5

From Hell's Heart I Spit At Thee  An old player has one more scheme

Afterwards--The Watchers Council survives. Angel Investigations did not. The fallout is still falling. 

Accounting--The Senior Partners have a schedule to keep, and it's time to settle things with a particular souled vampire

 

The Scent of Ancient Dust--Xander's gone back to Africa, and he's found trouble.  Spike and Ethan are sent to help.

(watch this space.  If my notes are anything to go by, we're far from done)