  The recent release of data on (i) high redshift source counts from NICMOS
HUDF, and (ii) electron scattering optical depth from 3-year WMAP, require a
re-examination of reionization scenarios. Using an improved self-consistent
model, based on Choudhury & Ferrara (2005), we determine the range of
reionization histories which can match a wide variety of data sets
simultaneously. From this improved analysis we find that hydrogen reionization
starts around z = 15, driven by the metal-free stars (with normal Salpeter-like
IMF), and is 90% complete by z = 10. The photoionizing power of PopIII stars
fades for z < 10 because of the concomitant action of radiative and chemical
feedbacks, which causes the reionization process to stretch considerably and to
end only by z = 6. The combination of different data sets still favours a
non-zero contribution from metal-free stars, forming with efficiencies > 2%.
