iOS 5.0.2 Delayed
iOS 5.0.2 may have been delayed so that Apple can fix memory leaks.
iOS 5.0 came with some horrible battery life for some. Luckily, iOS 5.0.1 came to rescue for some. Albeit it helped a good number of people, it didn't help all of them. Apple said that the battery problems were because of numerous bugs and that iOS 5.0.1 only fixed some of the bugs. They promised to fix the rest of the bugs in a future update. The future update is iOS 5.0.2 and it's going to be released in the near future. Unfortunately, it will be released later than we expected it to be.
It appears that iOS 5.0.2 has memory leak issues that Apple needs to fix. For that, they need to delay the release so that they can fix the leaks. A memory leak is when software uses memory although the program cannot use the data stored in the memory. This causes the program to use a ton of memory that it would not usually need. Since the iPhone 4S only has 512MB of RAM, memory is a very diminishable resource. In other words, memory leak on iPhone = no bueno. Apple engineers are hard at working plugging up the battery problems plaguing iOS 5. They are also improving Siri functionality with each release for the iPhone 4S.
As before, if you are looking forward to an untethered jailbreak for your iPhone 4, we recommend that you stay on iOS 5.0. If you updated to iOS 5.0.1 already, then you might as well update to iOS 5.0.2 because either way you're going to be stuck with a tethered jailbreak for a while!
iOS 5.0.2 will probably be released as a beta before we get to see it, so stay tuned and we will let you know when iOS 5.0.2 is released. Keep in mind that it likely will not have any new features. So again, if you're on iOS 5.0, stay on it! There is currently no way to downgrade iOS 5 releases on your iDevice. If you have updated, your best bet for an untethered jailbreak right now would be to downgrade to iOS 4.3.3 using your SHSH blobs.
Sources: Apple Insider