I just activated the 200 GB of free storage last nite on me and my wife's surface 2.
It worth it even when we have to start paying a $100 a year is a great price for all that storage!:excited:
The storage is free for two years, so yes it is worth it I think. Also, Bing has a promo where 100 Bing points gets you 100GB of storage for a year too. Microsoft is always giving away storage on OneDrive too, so go for it. At some point, the redemption code won't work (90 or 120 days after purchase I think?).
Right now with all the different promos, etc. I've got a little over 350GB of space, and I'm using half at this point. That means as old promos expire and new ones come up, I will probably be in okay shape. However, I am happy enough with the OneDrive integration in Windows 8.1 that probably will not have much of an issue paying for space if it comes to that. Microsoft's rates are way better than Dropbox and competitive enough with Box.