Going from 1.56% to 1.73% is an ~11% increase, which is a pretty large rise (albeit from a smaller base)
Meanwhile, XP's "huge" drop was 7%. Which is a fair drop, but I wouldn't call it huge.
Seeing this rise in Linux is promising.
I use Linux on the desktop but it has been a while since I have seen or heard of anyone making the move to Ubuntu or anything else install-yourself on the desktop. However I do know of lots of happy Chromebook users.
There is no headline story here as far as Linux is concerned. As I see it there is a very slow replacement rate for regular PC's - 10% market share in over a year looks to me like only 11% of PC's have been replaced in the last year. Given PC's are supposed to have an average lifespan of 5-7 years that means Windows really is not selling very well.
I'm perfectly serious, the cognitive dissonance that fact causes in Linux desktop enthusiasts is very revealing. If 'Linux' ever gets anywhere on the desktop, it will be one 'distro' (I prefer to call them Operating Systems) running one desktop environment with one primary application development framework that does so. That's because that fact that Linux has anything to do with Android, or FirefoxOS, or Ubuntu Mobile is basically irrelevant.
What actually matters is the UI layer and the development framework. That's why the fragmentation in Linux distros has killed any chance of Linux taking over the desktop. It's because the things that actually matter - desktop frameworks and development environments - are where the main fragmentation lies. For desktop dominance it's that desktop layer that has to be as unified, robust and compatible as possible.
Oh, and games. Definitely games.