What are the differences between Pandas and NumPy+SciPy in Python?
Numpy is required by pandas (and by virtually all numerical tools for Python).  Scipy is not strictly required for pandas but is listed as an "optional dependency".  I wouldn't say that pandas is an alternative to Numpy and/or Scipy.  Rather, it's an extra tool that provides a more streamlined way of working with numerical and tabular data in Python.  You can use pandas data structures but freely draw on Numpy and Scipy functions to manipulate them.
They both seem exceedingly similar and I'm curious as to which package would be more beneficial for financial data analysis.