Please define "decent OS"!

More to the point, is there a reason to believe, it will be running a mainline kernel with working modem (GSM calls) and reasonable power management?

Afaik Snapdragon has no reputation for being particularly Linux-friendly, but that knowledge is probably outdated.
I'm willing to compromise for a proprietary firmware here and there, but I'm not going to buy a device that needs proprietary kernel modules or other proprietary software for essential tasks.