A "panel discussion", on themes & plugins eh? A selected set of figures picked for their relevance & experience? And then there's a mixed audience?

And the moderator gets to ... keep things perking? Challenge assumptions & disturb complacency? Keep it entertaining for the audience?

1.) "Core vs Plugin". Matt Mullenweg in years past sang the praises of a small core that does little .... WordPress trending to become almost a mere Language. There's been some compromising ... but that may have come to a halt, with the version 3.6 fiasco.

2.) "Industrial Users vs Freelance Developers". It is very important that WordPress cater to major power-hitters in the big-time online publishing world. These entities often have their own inhouse WordPress shop ... they don't typically buy themes or plugins, they custom-build them, on-premise, using their salaried WP staff.

3.) "Websites vs Social". How to meet the challenge ... which Matt Mullenweg regrets not prioritizing earlier.

4.) "Kate Middleton vs Kim Kardashian". Rule Number One - don't let too many of those audience-chairs get empty! :)