The iPhone Dev Team anounced that found 3 (!) iOS 5.1 Jailbreak Exploits. However, some are just tethered as i0n1c mentioned at one tweet.
Till now, iOS 5.1 is ONLY TETHERED for A4 Devices.
Thus, what we can do is wait until an untethered jailbreak is publicly released!
When an untethered jailbreak is out, we will publish a new post on anything you need to know about it!