I've been using almost nothing else than Debian GNU/Linux on i386 and amd64 PCs, since 1992. (I helped birth Linux, and I was part of Debian for a long time.) I have been happy for myself, but speaking more generally, I think it'd be awesome, nay, AWESOME, if computing wasn't so homogeneous. Almost everyone is using Windows or Mac. Outside that, it's mostly Linux, with a few BSD variants. I hope to see that change, some day.
Ideally, radically different, not just another Unix.
However, having lived through the entire lifetime of Linux, it's not easy to develop an entire operating system, and its supporting ecosystem, if you need it to be usable with current and near-future hardware and common devices without extensive effort to set up and configure by users.
Copying drivers means copying some of the software architecture and bugs, too. Less heterogeneous.
(Just idly ranting, waiting for a test run to finish.)
@liw I think broad hardware support is not so important now. At least initially it's enough to be able to run in VMs, which have quite homogenous hardware.
It's the applications that matter. Somehow a new OS has to attract the developers that build a "killer app" (or range of apps) that lead to wider adoption. But I think it's increasingly hard to invent interesting new OS facilities or application areas. Everything has been done before, even if your new OS can do it much better.
Lars Wirzenius
Ben Hutchings