If you plan on jailbreaking your iPhone 4S or iPad 2 as soon as a jailbreak for Apple A5 chipset-powered devices is released, update to iOS 5.0.1 ASAP if you haven't already.

If/when Apple releases an iOS 5.0.2 patch or iOS 5.1 they'll most likely stop signing iOS 5.0.1 pretty quickly. iOS 5.1 patches the current exploit used on iOS 5.0.1. That means if you don't update before then, you'll be stuck waiting for jailbreak developers to find a new exploit for iOS 5.1 and we have no idea how long that'll take.

So the moral of this story is if you'd like to jailbreak sooner rather than later, update your devices to iOS 5.0.1 now. If you've got an iPhone 4 or other Apple A4 chipset device, you can jailbreak untethered now on iOS 5.0.1.