Hardkernel have already done a good job at bringing low cost, high performance development boards based on Exynos 4 Quad processor with boards such as ODROID-X, ODROID-U2, or ODROID-X2. But it appears they are not stopping here, and have recently committed code to support ODROID-XU development board based on Exynos 5410, the 8-core big.LITTLE SoC from Samsung, used in devices such as Galaxy S4.
The committed code linked above point the device tree files in arch/arm/boot/dts/ (exynos5410-odroidxu.dts and exynos5410-pinctrl.dtsi) where we can see the board will have 2 GB RAM, and the Cortex A15 cores with be clocked at 1.6 GHz. Exynos5410-odroidxu.dts has been removed from 3.11 branch, so the link above points to an earlier commit.
Exynos 5410 might have been the first big.LITTLE processor ever available, but it comes with a major flaw, as it only supports cluster migration (all 4 Cortex A15 or all 4 Cortex A7 enabled at the same time), whereas big.LITTLE processing also allows for finer control of processors. Samsung recently announced Exynos 5420 that should fix this issue and support Global Task Scheduling. Hopefully, 5410 and 5420 SoCs are pin-to-pin compatible, and ODROID-XU will get an easy upgrade.
Hardkernel is not the only company working working on an Octa-core board, as Insignal is said to be developing the Arndale Octa with Exynos 5410, which was planned for this month. However, considering the state of Arndale forum, and ARMBRIX Zero cancellation, something may not be right at Insignal, and Arndale Octa may never see the light of the day.