I don't know what's the final retail/bulk price of S31 and its modules will be, but S3 module with 16 MB NOR Flash and 8 MB PSRAM costs $3.5 for 500+ pcs, and the final PCB BOM cost is $4 or so.

According to Espressif website, current "reference price" for S31 sample module (1 piece) with 16MB flash + 16MB RAM is $6.2.

If S31 won't be much more expensive than S3 in bulk, it has a chance to become a very successful and what's more importantly really cheap full-featured Linux platform, in a small form factor, with flash, RAM, and radios integrated.

Espressif here could easily kill many contenders. You can count Wi-Fi-integrated Linux SoCs on one hand, let alone with RAM+Flash integrated, let alone cheap and available in quantities, and with reasonable soft and tech support.

Oh, and ESP module quite literally doesn't need anything more than a 3.3V power and maybe 2 capacitors to work.