They sent out a '72 replica jersey to all full season ticket holders. I think it is the renewal gift.
The Sox are also giving free stadium club passes for weekday games (M-Th) to season ticket holders in diamond, platinum, and gold boxes. The option to include the weekend games is available for $500. I have mixed feelings about the value of the stadium club but it is a nice little extra perk for paying the higher ticket prices.
I have gold box seats now and put in a request to upgrade to diamond if anything opens up but I have a feeling most if not all of those seats will be renewed even with the higher ticket prices.