Love them or hate them, the Eldrazi seem to have been established by Zendikar block to be major recurring villains down the line. Mark Rosewater has in the past promised the Eldrazi will be back, although likely without annihilator, the principal reason for the divided opinions about them.
Now, he has confirmed that one other feature of the Eldrazi is gone for good - When jcomstock asked "When the Eldrazi return, is there a possibility of bringing back tribal just for them?" Mark replied:
You have to go cold turkey when you get rid of something. Making an exception just stirs up the whole issue again.
The tribal card type - previewed in Future Sight as something for Lorwyn block's creature-types-matter themes - was the source of no end of design and rules problems in the years since. It did make a comeback for noncreature Eldrazi cards in Rise of the Eldrazi, in order to give a taste of what colorless magic of subjugation and repression look like. But since tribal has gotten the axe, even the power of the Eldrazi's not enough to revive it.