Justin Sun is a nobody to noncoiners. To those with cryptocoins he is mostly considered a successful, but scummy marketer.

It will boost price if true, but it won't actually make steem any better unless it attracts developers and development. Looking at Tron's other projects I doubt this could be a long term good.

If he buys SteemINCs stake, a fork to remove ninja mined Steem should happen. Play both chains or sell one and stck with the other.