Bitcoin adoption from the second most well known brand on the internet should generate a bigger price rally, and more secondary reporting of the fact than from just one bitcoin news site.
Yes I think if any of Facebook/Google/Amazon were confirmed to accept Bitcoin payments, it would drive the price up almost instantly anywhere between 2x and 10x. All signs so far point to fakery, the current rally I think is underpinned by the Fortress and Zynga news and not by this rumour.