Here are the results of running the same tiny program against 2.5.2,
30b2, and 30b3. The program creates a regex and tries to match 3
strings. For 2.5.2 and 30b2 this works fine; for 30b3 the regex won't
even compile:

$ python -V
Python 2.5.2
$ python /tmp/retext.py
name="name1" value="value1"
name="name2" value="value #2"
name="name3" value="value '3'"
$
$ ~/opt/python30b2/bin/python3.0 -V
Python 3.0b2
$ ~/opt/python30b2/bin/python3.0 /tmp/retext.py
name="name1" value="value1"
name="name2" value="value #2"
name="name3" value="value '3'"
$
$ ~/opt/python30b3/bin/python3.0 /tmp/retext.py
Traceback (most recent call last):
  File "/tmp/retext.py", line 8, in <module>
    """, re.VERBOSE)
  File "/home/mark/opt/python30b3/lib/python3.0/re.py", line 203, in compile
    return _compile(pattern, flags)
  File "/home/mark/opt/python30b3/lib/python3.0/re.py", line 255, in
_compile
    p = sre_compile.compile(pattern, flags)
  File "/home/mark/opt/python30b3/lib/python3.0/sre_compile.py", line
520, in compile
    groupindex, indexgroup
RuntimeError: invalid SRE code