Sony has done an excellent job at being transparent with its progress on the bringing Ice Cream Sandwich to a number of Xperia devices. It has kept users aware of what's going on throughout the process, as well as shared alpha and beta builds along the way. Now, though, it looks like the beta days are behind them and the build is ready for prime time for a certain Xperia devices.
The rollout will being with unlocked variants of the Xperia arc s, neo v, and ray (seriously, Sony, stop with the lowercase device names. It looks awful) in Nordic Countries and will continue over the next four to six weeks. From there, it will start to roll out globally as carriers allow.
The ICS update for the Xperia arc, PLAY, neo, mini, mini pro, active, and Sony Ericsson Live with Walkman should also be ready to roll in late May or early June according to the Sony Mobile Blog, but again, will require carrier approval in most situations.