Tickless system?

[walt]

I noticed that the linux kernel config menu introduced an item a few
months ago called 'tickless system':
 "This option enables a tickless system: timer interrupts will only
trigger on an as-needed basis both when the system is busy and when
the system is idle."
"...further development like full tickless systems, where the time
slice is controlled by the scheduler, variable frequency profiling,
and a complete removal of jiffies in the future."
AFAIK this kind of thing is orthogonal to the goals of this project,
but it still seems an interesting idea -- one which might eventually
be of interest here.  Dunno.
Any opinions on this tickless idea, pros/cons/relevance?