I have to admit I'm kinda ready for a new Metroidvania. Preferably something different, and the 3DS should have different graphics at least. After Order of Ecclesia I felt tired of the formula, but now... dunno... I could totally see myself exploring stuff IGA style again
If IGA should ever revisit the Metroidvania formula I think he should make the game world a bit like Ecclesia with countryside and maybe a village, but he should get rid of the overworld map and just make the game one big cohesive world, kinda lika Simon's Quest. No disconnected areas, no effin portrait "portals", just a great, big, beautiful,
varied 2D world that takes place in and outside of Drac's castle.
Heck, why don't he just remake Simon's Quest as his first 3DS project? If there's anyone who could pull this off, it's probably IGA, seeing how much experience he has with Metroidvanias. He should stay reasonably faithful to the source material but add his own touches with brand new SotN-quality graphics, expanded/altered areas and stuff like that. I guess he could possibly fuck up the story, but I don't care. It's the gameplay that counts.