QUESTION:
Is Pluto the 8th planet right now?

ANSWER from Ed Colbert on May 30,1996:
If you count the planets in order of their distance from the Sun, right now,
then yes, Pluto would be the 8th closest planet to the Sun.  However, out of
Pluto's 250 year long orbit, it is the 8th planet only 20 years out of that
time.  

Another way of counting the planets is to look at their average
distance from the Sun.  On average, Pluto is further from the Sun than 
Neptune so with that definition we'd still say that Pluto is the 9th planet.  
My own preference is to call Pluto the 9th planet even now but either way 
is just fine.