It was possible that you have the curiosity to experiment iOS 4.2.1 GM new features which was released yesterday to iPhone 4, 3GS, 3G, iPod touch 4G, 3G, 2G and iPad, if you still didn't, you can download and jailbreak it now from here. You will note that Cydia still have some issues, the matter which make jailbreak pointless for many.