Night Elf and Human ingame music just became better with the new tracks (Night Elves' Song and Last Days of the Alliance) which are perfect-fitting with their counterparts in the Reign of Chaos soundtracks. The Human song is more monastic and when the drums come in later, it reminds me of the RoC music. The Night Elf one fits in comfortably. The Undead song still sounds... undead, with drums here and there and eeries echoes.
However the Orc (Power of the Horde) sounds very out-of-place. This may be due to the change in composer to Victor Crews instead of Derek/Tracy. The style is notably different and barely Orc-like to me, at least in the Warcraft context. I still prefer the Orc music in the RoC soundtrack.
The rest ~1MB songs are individual themes which are mostly played during each characters' cinematic scenes during the campaign.