According to Samsung Mobile's India Twitter account, the Samsung Galaxy S II ("SGSII") has been delayed globally by "at least a month."
Relatedly, GSM Arena has confirmed that the SGSII has undergone a change in specification - bumping its dual-core Samsung Exynos processor up to a screaming 1.2GHz. The official SGSII microsite no longer lists the device's exact processor specs - furthering speculation that the change will probably be officially announced by Samsung at some point.
Could this be related to the decision to manufacture Tegra 2 versions of the SGSII? The Exynos is a fairly new chipset, and there's a possibility that Samsung has decided to have it power the company's upcoming tablets, the Tab 8.9 and 10.1, as well.