Well, just did a little searching since seeing this article (why I enjoy G+) and it appears that Y! Axis is being marketed explicitly to those with Apple products. If you're one of these individuals, then you can try out Axis.
However, if you're like 90%+ of the U.S. then you can get an add-on and use the search functionality (Which mimics the Google Chrome "Instant" functionality). I would've given it a shot (even though I shot them down), but they aren't quite ready from prime-time in my opinion (Which is why they released on a platform with less users first, in my opinion).
And yes, Yahoo! didn't change their UI enough over the years to keep me engaged. There is much they didn't do, actually...