According to what Boy Genius Report found in their logs, it seems that Apple has been field testing 2 new iPhone OS.
The first one is iPhone OS 3.1.3, which should be made available pretty soon. I don’t think any major features will come with 3.1.3 and the usual “bug fixes” are expected.
The second and most important is the discovery of iPhone OS 4.0. We won’t see iPhone OS 4.0 until the new iPhone comes out sometimes in June or July next year but it’s interesting to see that Apple is already working on it. I guess these iPhone 4G rumors are not rumors anymore…
I looked at my logs and couldn’t find any track of an iPhone OS 4.0. I guess Apple engineers aren’t reading this blog 😉