Well 4.2.1 is the current version. But the jailbreak is tethered. The jailbreak for 3.2.2 is not tethered. What you should do though is save your SHSH blobs for 3.2.2 while you still can just to be safe. Download TinyUmbrella and use that to save your SHSH blobs. If you don't do that you can't go back to an earlier firmware when Apple stops signing it.... any day now for 3.2.2.
The Firmware Umbrella - TinyUmbrella