Standard point of view: When we look at distant galaxies, we see that redshift is higher then expected so we conclude that the universe is expanding at accelerating rate. I don't see the logic here. When we talk about acceleration, we mean how velocity changes over time. If velocity over time increases - it means object is accelerating. If velocity was higher long time ago and becomes slower over time we have to conclude that velocity decreases over time (decelerating) instead.