It turns out that this year’s May 4th promotion will indeed be an astromech, but it will be the Star Wars saga’s most famous droid, R2-D2. Speculation had suggested that it would be 40268 R3-M2, but it seems that polybag will be delivered by other means.
The Brick Fan provides the news about this year’s promotional polybag. 30611 R2-D2 is an unusual change for the polybags as it is a brick-built version of the plucky droid who is usually represented as minifigure. The set instructions can be found here.
Coinciding with the launch of 75144 Snowspeeder, the polybag is usually available with a customer spend above a certain threshold. An exclusive poster is sometimes given away too, although this varies from year to year.