  In this research announcement we present a new q-analog of a classical
formula for the exponential generating function of the Eulerian polynomials.
The Eulerian polynomials enumerate permutations according to their number of
descents or their number of excedances. Our q-Eulerian polynomials are the
enumerators for the joint distribution of the excedance statistic and the major
index. There is a vast literature on q-Eulerian polynomials which involve other
combinations of Mahonian and Eulerian permutation statistics, but the
combination of major index and excedance number seems to have been completely
overlooked until now. We use symmetric function theory to prove our formula. In
particular, we prove a symmetric function version of our formula, which
involves an intriguing new class of symmetric functions. We also present
connections with representations of the symmetric group on the homology of a
poset recently introduced by Bj\"orner and Welker and on the cohomology of the
toric variety associated with the Coxeter complex of the symmetric group,
studied by Procesi, Stanley, Stembridge, Dolgachev and Lunts.
