Excel Data Reader is the way to go!
It´s Open Source, at http://exceldatareader.codeplex.com/ and actively developed.
We been using it for reading Tabular (and sometimes not so tabular) worksheets for a couple of years now (In a financial application).
Works like a charm to read unit test data from human-readable sheets.
Just avoid the feature of trying to return DateTime's, as, for Excel, DateTime's are just double numbers.