  Numerical simulations of the intergalactic medium have shown that at the
present epoch a significant fraction (40-50%) of the baryonic component should
be found in the (T~10^6K) Warm-Hot Intergalactic Medium (WHIM) - with several
recent observational lines of evidence indicating the validity of the
prediction. We here recompute the evolution of the WHIM with the following
major improvements: (1) galactic superwind feedback processes from galaxy/star
formation are explicitly included; (2) major metal species (O V to O IX) are
computed explicitly in a non-equilibrium way; (3) mass and spatial dynamic
ranges are larger by a factor of 8 and 2, respectively, than in our previous
simulations. Here are the major findings: (1) galactic superwinds have dramatic
effects, increasing the WHIM mass fraction by about 20%, primarily through
heating up warm gas near galaxies with density 10^{1.5}-10^4 times the mean
density. (2) the fraction of baryons in WHIM is increased modestly from the
earlier work but is ~40-50%. (3) the gas density of the WHIM is broadly peaked
at a density 10-20 times the mean density, ranging from underdense regions to
regions that are overdense by 10^3-10^4. (4) the median metallicity of the WHIM
is 0.18 Zsun for oxygen with 50% and 90% intervals being (0.040,0.38) and
(0.0017,0.83).
