I am very excited for the shift to two formats, at least assuming that it essentially doubles what we have right now: separate ECR, separate reward pools (each the same size as the current ones), separate daily quests and end of season rewards, etc. That's what it sounds like we'll be getting, but I won't count on it until it's been made official. Anyway, if we get all that, then I will be very happy to play both of them to the best of my ability. If nothing else, it will let me play twice as much Splinterlands without hurting my ranking/ECR.
Unless it turns out that modern is much too competitive for me, that is probably where I will focus most of my efforts. I'll acquire cards to improve my performance in modern and take whatever boost they give me in wild as a secondary benefit. I'm a little bit worried about keeping track of both formats at once, as far as what deck archetypes I need to worry about countering and what cards I have available to counter them with, but I expect that will become second nature over time.