Is there a known date/timeframe when python 2.7 will not be supported any more in favor of python 3?
As of 13 Apr 2014, from http://hg.python.org/peps/rev/76d43e52d978 (PEP 373, Python 2.7 Release Schedule):
The End Of Life date (EOL, sunset date) for Python 2.7 has been moved five years into the future, to 2020. This decision was made to clarify the status of Python 2.7 and relieve worries for those users who cannot yet migrate to Python 3. See also PEP 466.