I'm not sure if that's deliberate, but the new attributes don't appear in the result repr():

>>> s = os.stat("LICENSE")
>>> s
posix.stat_result(st_mode=33204, st_ino=524885, st_dev=2053, st_nlink=1, st_uid=500, st_gid=500, st_size=14597, st_atime=1307474138, st_mtime=1299630588, st_ctime=1299630588)
>>> s.st_mtim
(1299630588, 90781883)

In the docs, you also need a "versionchanged" tag to mention that the attributes were added in 3.3.

The patch fails to compile under Windows: MSVC forbids variable declarations after code (atim, ctim, mtim), you have to put them at the beginning of a block. Once this is fixed, it seems to work ok.