If you're an OEM, how would you target these people? As long as you can get a clean, attractive, easy-to-use OS, you'll take an interest in one that's easy for you to customise, and ship with solid default apps, some of which you can monetise on. I think Firefox OS offers that possibility to OEMs, they get to completely control the experience and keep the relationships with customers. And the customisation process - being HTML5 - is arguably simpler and less of a specialised skill.
We're also working with plenty of other partners to bring this to other areas, so there is definitely interest.
I think what appeals to them is the open, customisable nature. Also, remember that this isn't meant to compete with Android and iOS, it solves other problems beyond performance and feature-set.
See also item two in the list at http://www.readwriteweb.com/archives/how_to_spot_openwashing...