Mavericks will not spike the Mac Uptake, because...
There is no question that the Apple hardware is nice, the MacBook Pro and Air are really nice machines, and at couple of the companies I have worked with recently I have noticed a massive uptake in Apple laptops, mainly the Air because of its size, weight and battery life. Strangely, when you walk round the other side of desk and see the screen 90%+ have ditched OSX and have put Win7 on, not IT enforced, but by personal choice because they find it easier to work with.
I have also tried to move to OSX for work but also found it nowhere near as productive (and, yes - I did try it for 3 weeks to get over the learning curve), having said that, I did by a mac air for home use and in that scenario find it great for web/email/music/dvd/photos etc
It would be interesting to know how many of the Apple laptops sold are still actually using OSX.