  We present an updated measurements of time-dependent CP asymmetries in fully
reconstructed neutral B decays to several CP eigenstates containing a
charmonium meson. The measurements use a data sample of (347.5 +/- 3.8) x
10^{6} $\FourS \to B\Bbar$ decays collected with the babar detector at the
PEP-II B factory between 1999 and 2006. We determine sin2beta = 0.710 +/-
0.034(stat) +/- 0.019(syst) and |\lambda| = 0.932 +/- 0.026(stat) +/-
0.017(syst). Both of these results are preliminary.
