  We present multi-epoch VLBA imaging of the 28SiO v=1 & v=2, J=1-0 maser
emission toward the massive YSO Orion Source I. Both SiO transitions were
observed simultaneously with an angular resolution of ~0.5 mas (~0.2 AU for
d=414 pc). Here we explore the global properties and kinematics of the emission
through two 19-epoch animated movies spanning 21 months (2001 March 19 to 2002
December 10). These movies provide the most detailed view to date of the
dynamics and temporal evolution of molecular material within ~20-100 AU of a
massive (~>8M_sun) YSO. The bulk of the SiO masers surrounding Source I lie in
an X-shaped locus; emission in the South/East arms is predominantly blueshifted
and in the North and West is predominantly redshifted. In addition, bridges of
intermediate-velocity emission connect the red and blue sides of the emission
distribution. We have measured proper motions of >1000 maser features and find
a combination of radially outward migrations along the four arms and motions
tangent to the bridges. We interpret the SiO masers as arising from a
wide-angle bipolar wind emanating from a rotating, edge-on disk. The detection
of maser features along extended, curved filaments suggests that magnetic
fields may play a role in launching and/or shaping the wind. Our observations
appear to support a picture in which stars with M ~>8 M_sun form via
disk-mediated accretion. However, we cannot rule out that the Source I disk may
have been formed or altered following a close encounter. (Abridged).
