Here are just a few of bullet points from the interview. I highly recommend reading the entire thing here.

Next Fest Feedback:

"It was over 120,000 messages just on the chat, and so I think we ended up having about 200,000 bits of feedback to pass, which was a lot"
"The biggest example of feedback, which we know is going to be crucial for us to nail in the main game, is how our group finder works."
- "...it's important to make finding parties friction-less so players can get into a game as quickly as possible."

Hero Based Gameplay

"As we bring in new heroes into the pool, it won't necessarily upset anyone because if we bring someone that's kind of out of left field, that could be the meta for a season or two, or if something falls out of favor in the meta. We aren't going to have that issue where that's the character that someone has created, and then they don't have relevance in the game anymore. "
"I will add that one of the things that I think we've tried to do more of an explicit job with is showing just how much the gear impacts the visual appearance of the hero you're playing."

Hero Count for Early Access

The next time people see our new build for the game, we will have three tanks, five DPS, and a couple of healers. So, we'll have around 10 heroes when people see the next roster we're ready to share.

Community Director Interview with MMORPG.com