Sony Ericsson has already confirmed that the newly announced Xperia arc flagship will launch with Android 2.3 (Gingerbread). However, Tweakers.net found out that one of their Xperia arc prototype units was running the as-yet unannounced Android 2.4.
Honeycomb is believed run under the Android 3.0 codename, so it’s unclear exactly what Android 2.4 is. It could be a slight revision to the Gingerbread code, much like when Éclair was revised from Android 2.0 to 2.1. Possible changes include a new animation when deleting icons off the home screen, as well as support for video calling. When quizzed about this earlier today, Sony Ericsson UK were not aware of units running anything but Android 2.3.1 on prototype Xperia arc handsets.

Via Endadget.