ElementTree - Why not part of the core?

[Gregory Petrosyan]

gregory at home:~$ python
Python 2.5a0 (#1, Dec 14 2005, 14:11:55)
[GCC 3.3.5 (Debian 1:3.3.5-8ubuntu2)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import xml.etree.ElementTree as ET
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.5/xml.py", line 20, in <module>
    import xmlcore
ImportError: No module named xmlcore
>>>