So many rumors, complaints, confused people. I want to help clarify a few things about the jailbreak community and upcoming releases.
First, I want to speak about the time it has taken for 3.1.3 to be jailbroken. Many think this indicates that Apple has won or that the jailbreak is just too hard. This is far from the truth. The fact is that 3.1.2 and 3.1.3 are really basically the same firmware. 3.1.3 was not “worth” doing a jailbreak for. Jailbreaks are done by finding a bug in Apple’s software and then exploiting it in some way that allows for the device to be compromised. At that point, the jailbreak software bundle is uploaded to the device and executed. When this completes, root access is achieved on the device.
Every time a jailbreak is released, Apple analyzes how it was accomplished and fixes the bug that was used to jailbreak the device. Quite simply, 3.1.3 was not worth giving this bug to Apple to fix it.  However, Apple has since released the iPad. This has become worth using up an exploit to jailbreak the iPad. As of today, the main iPad world wide release has not yet occurred. Spirit should be close to ready when it does.
At this point, there are *at least* two known exploits that have been used to provide jailbreaks. The first one we will see is from Comex and is called Spirit.  The next one is either from Geohot and is called LimeRa1n or Chronic dev called Greenpois0n.  Here are some infos on these jailbreaks:
Spirit - There is no current release date (no, it will not be Friday as rumors say). This will work on all device to date and will not be tethered. This will jailbreak 3.1.3 and 3.2 (iPad) devices.  This jailbreak will require that your device is activated. That means, if your device says only “slide for emergency” you cannot use this jailbreak until you insert a valid sim card and activate the device. After that, you can jailbreak. Therefore, there will be no unlocking on Spirit. For those running 3.1.2 that wish to update to 3.1.3 and use Spirit, you cannot do so if you require an unlock. It is also unclear if a 3.1.2 version will be released to simply untether those of you that are on 3.1.2 (spirit currently requires a stock unjailbroken device to work). Spirit is real and it works very well. The current version is command line and a GUI is being written for it for both Windows and OSX.
Spirit, while originally found and done by Comex alone, is being made into a product using the cooperation of many teams (iphone dev team, chronic dev team, as well as Comex).  As we should all understand, getting a jailbreak from exploit to usable tool is quite a bit of work. Especially on a new device like iPad where many tools have to be rewritten or updated (like Cydia).
LimeRa1n - This is what Geohot is calling his jailbreak. Originally it was going to be released for iPad first, but instead Geohot got busy and is holding it for 4.0 (possibly to be completed by Chronic dev team). There may be an unlock planned by Geohot after 4.0 is released but its not clear yet. This jailbreak will not require an activated device and works differently than Spirit in that sense. In addition, there is a tethered and non-tethered version of this. It is not totally clear yet, but it may be possible to stretch this into two jailbreaks, one tethered and one not.
Greenpois0n - This uses the same exploit that Geohot found and was being worked on by posixninja of the Chronic Dev Team. Greenpois0n is more of a toolset that can be used to find other jailbreaks, firmware decryption keys, and may be useful in the future. When it will be released is also unclear.
How does this affect you?
Here will be your options when Spirit is released shortly:
1) You are on iPhone 3gs and are a subscriber to a contract carrier like AT&T. You will be able to update to 3.1.3 and jailbreak your device non-tethered.
2) You are on iPhone pre-3gs - you can update to 3.1.3 and jailbreak today with redsn0w.
3) You have a device that is not an iPhone (its an ipod touch any generation or an ipad) - you can update to 3.1.3 and use Spirit to jailbreak.
4) You have an iPhone unlocked and on 3.1.2 tethered. You will have to wait. Spirit will probably not work for you. If you update to 3.1.3, your baseband will be updated and you will not be able to unlock again.
5) You are on 3.1.2 and happy. Just install “3.1.3 firmware app”, click “3.1.3″ then “reboot” and you are as good as anyone that restored to 3.1.3 and jailbroke. Everything in appstore that requires 3.1.3 will work now.
In any case, you guys will want to keep your shsh stored in Cydia. 3.1.3 shsh’s will become valuable soon.