I have a feeling it'll be 2GB. While iOS 7 seemed to work fine on a 5s with 1GB RAM, the added features of iOS 8 as well as the ability to have more information displayed within an app within landscape (thus requiring more resources), it might just happen. We'll probably see once the reviews for the phones are out of the embargo next Wednesday (or if the reviewers happen to go a GeekBench test and have it public).