Psychic has gone a long way towards regaining its former lustre, yes. Magic Guard for Alakazam, Magic Bounce for Espeon and the introduction of Reuniclus really helped improve the type's presence in OU. Not to mention Psyshock giving them some much needed help against Blissey.
For me it really is Poison that needs the biggest boost, but Grass could do with help too. I think the type matchups for Grass are fine, it's just the pokémon themselves that let the side down. The movepools are in serious need of expansion - a movepool comprised solely of Grass and Normal type moves simply doesn't cut it.