basically the new units fix a dozen of problems. imo
viper is just anti protoss death ball with stalkers/colosus/sentries (forcefields)
swarm host is pretty weird.. i guess it is just a basic harass unit/maby possibile cheese factor?
i seriously have no idea what the replicant is for

seems pretty random
oracle is probably to make the protoss play style much more skillful and not just gay allins, now the protoss players actually have to be good cuz macro will be alot more valid ( because it helps protoss keep up the pace ) in such kind of play that we dont see, or rarely do
tempest is probably just to encounter any kind of air play by zerg or terran, probably forces the pvz to go into the hydra roach viper style which i think will flatly crush deathballs instantly, have no idea what effect it will have in tvp
the terran units make no sense

I agree with you a lot on this one. Terran by far got the short end of the stick here. Although with the new Thor replacement I do see a much better air defense for T. Those Swarm Host's though I see DEFINITE potential. I mean burrowed, forces additional Scans from CC. Which COULD increase Burrowed Baneling play. Think about all the added scans they are going to need with a Swarm Host/Burrowed Baneling strat. PvZ Swarm Host's would be almost pointless. Although as stated possible Swarm Host drops on mineral lines for both T or P matchups would be nice.