Coming as the little brother of the Galaxy S II I9100, the Galaxy R / Z features a 4.2 inch S-LCD WVGA display, 1GHz dual-core Nvidia Tegra 2 processor, 5MP rear camera with 720p video recording, 1.3MP front-facing camera, 8GB of internal memory, and a metallic back case (which makes it a bit heavier than the S II: 135g vs 116g).
According to Cnet, the Galaxy R will be available to UK customers before he end of July, thus starting the next couple of weeks.
source: Unwired View