Yeah, it's brand new as far as you would consider in practice (they use existing libraries and the like).
The answer is not much time. The real question is how long to develop good quality drivers for a give platform (say, an x64 laptop)? How long to port/develop applications so that the OS is useful? How long to convince OEMs, app developers and such folks to start using your brand new OS? It's a bootstrap problem.
The answer is not much time. The real question is how long to develop good quality drivers for a give platform (say, an x64 laptop)? How long to port/develop applications so that the OS is useful? How long to convince OEMs, app developers and such folks to start using your brand new OS? It's a bootstrap problem.