This article speaks as if it was 100% certainty that Zynga's announcement caused the fluctuation. Doesn't feel entirely accurate.
It's similar to every single day's coverage of financial stocks -- "The stock is up 1% on the expected change in the price of tea in china."
Worthless.
I think there's another factor that is driving the price up more than anything else - serious hoarding by people who are just now beginning to understand the system and how it works.