Judging by the screenshot below, the Android 2.3.3 update for the Xperia arc and Xperia PLAY will soon be hitting the handset. This particular user has been running the 3.0.1.A.0.145 firmware for only a day, so we don’t know what the main improvements are.
Interestingly, the latest firmware certified on PTCRB is 3.0.1.A.0.143, so version 145 has yet to be certified. However, he says this is likely to be the publicly released version and says the update could arrive as soon as week 21/22 i.e. by the end of May. More news as we have it.
Via xda-developers.