Use 'speed' instead of 'performance', because I agree with the argument
at http://zestyping.livejournal.com/193260.html that 'erformance' really means
something more general.
diff --git a/Doc/whatsnew/whatsnew25.tex b/Doc/whatsnew/whatsnew25.tex
index acb5bdb..b5a5236 100644
--- a/Doc/whatsnew/whatsnew25.tex
+++ b/Doc/whatsnew/whatsnew25.tex
@@ -1136,7 +1136,7 @@
and as a result sets will use a third less memory and are somewhat faster.
(Implemented by Raymond Hettinger.)
-\item The performance of some Unicode operations, such as
+\item The speed of some Unicode operations, such as
finding substrings and character map decoding, has been improved.
(Substring search improvements were added by Fredrik Lundh and Andrew
Dalke at the NeedForSpeed sprint. Character map decoding was improved
@@ -1428,7 +1428,7 @@
included in the \file{Tools/pybench} directory. The pybench suite is
an improvement on the commonly used \file{pystone.py} program because
pybench provides a more detailed measurement of the interpreter's
-performance. It times particular operations such as function calls,
+speed. It times particular operations such as function calls,
tuple slicing, method lookups, and numeric operations, instead of
performing many different operations and reducing the result to a
single number as \file{pystone.py} does.