Pulled this into the sprint as this is blocking the user-testing card.

Preliminary investigation tells me that this would involve changing the way the prototype is designed significantly.

As far as I understand, the slider on WordPress makes the tipsy appear on the handle (as opposed to the slider), and dynamically changing its value based on its position. This allows it to make the dragging more granular (and not jumpy as we have it now). This is certainly a very good idea to explore and keep in mind when we develop the actual extension, and probably easier to implement too when we are not using the default bare-bone jQuery slider. But right now this is certain to take up ~2-3 days (optimistically speaking) to implement.

@DannyH: Given Niharika's assessment that this will take some significant refactoring of the gadget (~3 days), should we keep this as a blocker of the user test or do the user test without this change?

I did guerilla user testing with three people in the office this afternoon.
The test was: start on the history page, choose revisions to compare, get
to the slider and then: "play around with this for a minute".

In all three cases, they figured out immediately that you get the hover
info when you're hovering on the slider. When they moved their mouse off
the slider and lost the hover, they moved back to the slider.

So: I was wrong, this is apparently not a huge blocker. :) Let's talk about
doing the user testing.

@DannyH, they are all engineers (who have worked with MediaWiki gadgets before, no less!). :P I'm going to grab few community people on IRC today and see if I can get them to test it.