Calling it now: Taric will be nothing more than a walking AoE Kayle ult

Yeah... no. After playing him on the PBE he is nothing like Kayle.

Because of the invulnerability delay you don't use it to save people from lethal damage, you use it only to prevent early damage in a fight. You use it at the start of an all out brawl so that it can block a large portion of burst early on, rather than keep a carry standing toward the end of the fight.

It may look a lot like Kayle's ult, but it plays completely differently.

Taric does it all... with style.

For real though, his ult is nothing like Kayle's. The delay makes it harder to time and you can't waste it on your Bastion-partnered ally if they're in the thick of it because they'll be dead before it'll take effect.

Oh yeah, tell me about all of those supports that have a stun and Lane Sustain built into their kit. Oh, you cry Sona and Nami? Tell me about how both of them are tanks

If I had to guess, he likely won't be used bottom as often as Riot intends. He'll likely be utilized in toplane more often due to his innate tankiness, the massive dueling power he gets from his passive and his relative safety post-6.