Can rkt+kubernetes provide a real alternative to Docker?

Last week in LinuxCon/ContainerCon Berlin, I attended a presentation by Luca Bruno of CoreOS, where he described how kubernetes, the most popular container orchestration and scheduling service, and rkt integrate. As part of the presentation, Luca delved into the rkt architecture. For those unaware - there are many, which is a major part of the problem - rkt (pronounced "rocket", as in this) is CoreOS's container management implementation. Nowadays, almost everyone who thinks containers, thinks "