Rehgar hasn't changed too terribly much and is still super strong for main support. About all they have done is make your tier 3 talent enemy team comp based. I like using cleanse against a CC heavy team, however if the team has an enemy Zeratul or Nova on it then you may want farsight. Farsight can also be very helpful for maps such as Spider Queen Lair to see if the team is turning in or Dragonshire to see how many enemy team members are waiting at mid or at a capture point. If neither are a factor then you may go earth shield, but the rework has made it a much less viable talent to take.

The level 20 talent can go one of two ways. Rewind is great for bursting a team that is desperately in need of heals. A couple lightning shields and a totem or two can also swing a fight in your teams direction. Storm shield use to be what I took every time and it is still helpful, but being able to spam out two big heals at a clutch moment can be key to winning a team fight.