  We report the detection of radio emission and orbital motion from the nearby
star-brown dwarf binary WISE J072003.20-084651.2AB. Radio observations across
the 4.5-6.5 GHz band with the Very Large Array identify at the position of the
system quiescent emission with a flux density of 15$\pm$3 $\mu$Jy, and a
highly-polarized radio source that underwent a 2-3 min burst with peak flux
density 300$\pm$90 $\mu$Jy. The latter emission is likely a low-level magnetic
flare similar to optical flares previously observed for this source. No
outbursts were detected in separate narrow-band H$\alpha$ monitoring
observations. We report new high-resolution imaging and spectroscopic
observations that confirm the presence of a co-moving T5.5 secondary and
provide the first indications of three-dimensional orbital motion. We used
these data to revise our estimates for the orbital period (4.1$^{+2.7}_{-1.3}$
yr) and tightly constrain the orbital inclination to be nearly edge-on
(93.6\deg$^{+1.6\deg}_{-1.4\deg}$), although robust measures of the component
and system masses will require further monitoring. The inferred orbital motion
does not change the high likelihood that this radio-emitting very low-mass
binary made a close pass to the Sun in the past 100 kyr.
