We now know when Vanillaware's HD remaster of Odin Sphere, Odin Sphere Leifthrasir, will be turning up: they've announced the release date as June 7. It'll be available both digitally and in disc form for Playstation 3, Playstation 4 and Vita.
The rerelease will be more than just a hi-res enhancement. Vanillaware will be updating the combat and RPG mechanics, and adding some new content. They're still keeping mum on just what will be new, but they do mention additional monsters and new fully-voiced cutscenes. Just as long as sheep still grow from plants.
An 8-bit throwback version of Odin Sphere is also in the works as a promotional tool, but it won't be released outside of the webpage it'll be embedded in. Atlus still hasn't revealed when that version will be released, but I'd imagine they would prefer to get it out while the remaster is still new in stores.
Odin Sphere was originally released on the Playstation 2 in 2007. If you missed it then, don't miss it now.