Hammerdins are still S-tier. Only change to hammers is now they don’t ignore magic damage, I.E. all of like a few packs of monsters here and there, most notably the 2nd minion pack before Baal. Conc does still work on hammers. And yes you can respec, you get the ability once per act by completing the den of evil quest. So a total of 3 easy respecs. More can be obtained end game in a new side quest, similar to collecting organ-sets. Respecs reset everything, skill points and stat points. So the grind through normal shouldnt be nearly as bad anymore now that you don’t have to save up skill points for end of tree skills.
There are some changes, but the tiers on classes will be similar in the end. Expect pally and sorc gear to be at a premium, summon necs are still great to start untwinked, even better due to the increase in damage in corpse explosion.
The only two really awesome things to come out of this patch are the respecs, and the increase in rune drop rates. Finding legit high runes is no longer an impossible task, they really buffed the drop rates a lot.