Just keep an eye on what Surly are doing, they were first (or thereabouts) with production fatbikes and 29ers, and now they’re pushing the ‘plus’ sizes in both 26 and 29inch variants.
The partnership between Surly and Salsa is both interesting and effective. Surly create the niche and a once it’s established Salsa provide the bling for those who want a little bit more without Surly having to alienate it’s core customers by moving away from it’s ‘steel is real’ and ‘bikes just for riding’ corporate philosophy.