  We present new, high dynamic range VLA images of the inner jet of the closest
radio galaxy, Centaurus A. Over a ten-year baseline we detect apparent
sub-luminal motions (v ~ 0.5c) in the jet on scales of hundreds of pc. The
inferred speeds are larger than those previously determined using VLBI on
smaller scales, and provide new constraints on the angle made by the jet to the
line of sight if we assume jet-counterjet symmetry. The new images also allow
us to detect faint radio counterparts to a number of previously unidentified
X-ray knots in the inner part of the jet and counterjet, showing conclusively
that these X-ray features are genuinely associated with the outflow. However,
we find that the knots with the highest X-ray to radio flux density ratios do
not have detectable proper motions, suggesting that they may be related to
standing shocks in the jet; we consider some possible internal obstacles that
the jet may encounter. Using new, high-resolution Chandra data, we discuss the
radio to X-ray spectra of the jet and the discrete features that it contains,
and argue that the compact radio and X-ray knots are privileged sites for the
in situ particle acceleration that must be taking place throughout the jet. We
show that the offsets observed between the peaks of the radio and X-ray
emission at several places in the Cen A jet are not compatible with the
simplest possible models involving particle acceleration and downstream
advection together with synchrotron and expansion losses.
