I can't speak for anyone but myself (and my facebook posting about this has generated quite a bit of discussion about this amongst my friends), but this will result in me spending less at Amazon, as well as not renewing Prime next year. Prime is great for things I don't need today, but would love by the end of the week (2-day shipping). It's great for the one time every couple years I need something tomorrow with $3.99 overnight. The video services I don't use (hulu + netflix), and I don't do the kindle sharing thing. The Kindle itself has replaced almost all of my book buying habits, with the exception of technical books, which I still prefer in dead-tree edition. This has reduced the need to actually ship things to me. Over the last year or so, I've begun exploring stuff like buying toiletries via Prime, just to make it semi-worthwhile. I still don't use Prime to order computer parts, or giant TVs and the like as I'd rather have a local return point vs. packing and shipping defective items, etc, but I could be convinced if the value was there. Basically, at $79 a year, I felt that was fair enough that I didn't even bother to create a new account with my educational email address to pay the student rate. At $99/year, that value proposition no longer holds true for me. Your mileage may vary, of course.
So, after my Prime runs out, I'll be shopping more locally and maybe paying a little more, to get the things I normally would have ordered from Amazon. Oh well, such is life.