reduce to be removed?

[Dustan]

According to the following page on Wikipedia:
http://en.wikipedia.org/wiki/Python_%28programming_language%29#Future_development
reduce is going to be removed in python 3.0. It talks of an
accumulation loop; I have no idea what that's supposed to mean. So,

===============================
>>> x =\
[[1,2,3],
 [4,5,6],
 [7,8,9]]
>>> reduce(lambda a,b:a+b,  x,  [])
[1, 2, 3, 4, 5, 6, 7, 8, 9]
===============================

What's an accumulation loop, and how would I convert this code so it's
compatible with the future 3.0 (preferably in a short sweet expression
that I can embed in a list comprehension)?