I reserved my copy on all my machines that qualify.
I know it got a bad rap, but I actually kindof dig Windows 8 on my Venue 11 tablet/laptop hybrid. The new UI takes some getting used to, but it works great on touchscreen devices. For desktops, using a mouse, it just plan sucks.
My main machine, and the one I spend the most time on running my business and doing my job, is Windows 7 and will probably stay that way for awhile. Upgrades are always hugely disruptive whether they "go well" or not and I'm not about to lose a couple days work just to be on the latest & greatest. I'll put it on my tablet, and probably my laptop which I use while on the road, but my primary machine is staying on Win7.
As for the whole subscription thing - yeah, it's probably coming. Everyone suspected it when Microsoft announced Win10 would be a free upgrade. Win8 is so tightly integrated with OneDrive and their other cloud services, they're pushing the whole SaaS (Software as a Service) model pretty hard.
It'll be awhile until they go to a full subscription model, if at all. Time will tell. I won't say it's impossible, but I doubt MS is going to just say "hey, by the way, you have to start paying $50/year now to continue using Windows 10." I do, however, seeing them turning Win10 into a subscription-based model for new features and upgrades.