RAX will get bought out within the year, and maybe within the week if the buyer wants to get it cheap enough. The buyer I've heard most commonly talked about is Hewlett Packard, also Amazon as you mentioned and IBM and Google, but the most likely is HP.
The call buying today was very new news, and both RAX and SVVS are both up after hours. RAX is up almost $2 after hours, something is definitely up after hours. My guess is either Microsoft or Amazon mentioned possible cloud aquisitions soon.