Not so. UNIX time is strictly defined in POSIX, as are the arithmetic relationships between it and human time, e.g. a time_t % 60 gives you the elapsed seconds in the current minute, which would not be true if unix time included leap seconds.
What you are describing is TAI, or International Atomic Time. If you were to choose to run your system on TAI, you would need some conversion routines if you wanted your system to remain POSIX compatible (which is what modern unix/linux apps expect) -- e.g. time() and stat() would need to continue to report unix-time values, and you'd need TAI-compliant library functions to request the equivalent items with their raw TAI values.
For more details, see the Wikipedia entry on Unix time.
Colbert hasn't announced if he will be running as a Democrat, Republican, both, or neither. Nor has he announced who his running mate will be, although he did toss out three possibilities: "Colbert-Huckabee, Colbert-Putin or Colbert-Colbert" He will, however, be running as a favorite son in the South Carolina primary."After nearly 15 minutes of soul-searching, I have heard the call... I shall seek the office of the President of the United States"
"Luke, I'm yer father, eh. Come over to the dark side, you hoser." -- Dave Thomas, "Strange Brew"