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. This could lead to a component shortage - and perhaps in light of this Samsung will debut Tegra 2 SGSII handsets at launch, and later upgrade to the Exynos chipset. This may explain the jump in processor clock speed, but that's just speculation.
Needless to say, we'll be keeping a close eye on this one.