As a high-ranking Samsung executive confirmed "Korea Times" on Monday, Samsung will use its own Exynos-branded ARM-based quad-core CPU "in the Galaxy S II's (aka Galaxy S III) successor". Furthermore he confirmed that Samsung's single-chip solution, which will be used for the S III, is a combination of LTE and W-CDMA functions, which means Samsung will lower its dependency on Qualcomm, which was so far the number one chip provider for W-CDMA (UMTS) based smartphone chips. Samsung already made some first Android experiences with Google's Samsung Galaxy Nexus phone which is already using Samsung's own telecom chips.
It shouldn't be a surprise that Samsung will use its own Exynos quad-core chip instead of a Qualcomm solution, especially after Qualcomm is still not ready to provide manufacturers the reference design but this move will also increase profitability for Samsung and Samsung is not alone. Also Huawei announced at the recent Mobile World Congress that it will manufacture its own ARM-based chips to get more independent of Qualcomm by having more control about the chip's functionalities and design.
Samsung has not yet officially announced the Galaxy S III but it's expected that it will be made public anytime later this spring.
Cheers ~ Arne