Cheapo includes the ONML tilesets, but unlike the Orig ones, they're not remade, they're just copied straight from ONML. They do contain some pieces ONML doesn't though, such as 90-degree rotated versions of the straight bars in the snow tileset, and steel in the bubble tileset (well, NeoLemmix / newer versions of Lemmix include steel in the Bubble set nowadays, but vanilla ONML sure didn't).
New tilesets at the moment seem to be fairly rare... there's the odd one showing up now and then for Lix, and there's a decent chance that whenever I announce a new project, it also means a new NeoLemmix tileset or two. Traditional Lemmix, Lemmini and SuperLemmini aren't getting much at all. That being said, expect to see a LOT of the old Cheapo tilesets (and there were
a LOT of these) showing up on NeoLemmix too in the near future.