Ten Year Rule

I was thinking recently, and I know that the general threshold for discussion on this list is ten years, but is that enough? As it stands, given the rule of a minimum of ten years, most early Pentium III PeeCees are listworthy for discussion. I have a Dell OptiPlex GX110 that could be discussed here; the machine is twelve years old, and if I am not mistaken, twelve is greater than ten. (For those of you that live in alternate realities in which twelve is *not* greater than ten, please disregard this whole email.) I also have an Apple iMac G3 Rev. B that could be listworthy, as it is eleven years old. In just two more years time, the world's most popular computer operating system (as of the time of this email's writing) would be perfectly valid to discuss, even as "on-topic". 2001 to 2011 is ten years, isn't it? I know that it's not a strict and absolute rule, being more just a guideline than anything, but still, is ten years enough? Personally, I'd give it fifteen, possibly twenty years for some piece of computing history to be considered listworthy.