At the moment, it looks like the new Ruger/Marlins will be .45-70, with .30-30 to follow. The 1894 in .357 and .44 - - maybe .45C - - would likely be next. The excellent but less mainstream .38-55? Who knows when, if ever?
.45-70 is common, easy, and extremely capable with a lot of options that range "from tactical to nuclear"