This is not a bug:

-1 ** 2 is parsed as -(1 ** 2), not (-1) ** 2.  Take a look at:

http://docs.python.org/reference/expressions.html#the-power-operator

In -1 ^ 2, ^ is the bitwise exclusive-or operator, not the power operator.

pow(x, y) is indeed equivalent to x**y:

Python 2.6.2 (r262:71600, Aug 22 2009, 17:53:25) 
[GCC 4.0.1 (Apple Inc. build 5493)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> x = -1
>>> y = 2
>>> x ** y
1
>>> pow(x, y)
1
>>>