I vaguely remember that parts of the GSM protocol were also described using ASN.1 (BER). I'm not sure how relevant this is for newer cellular network protocols, though. But if so, that makes it unlikely it will go away soon.
Since it was standardized by ITU, it's still used in newer telecom protocols, and it's pervasively used throughout higher level cryptography-related protocols/standards, CAdES is one of the more recent ones and gaining acceptance in the EU. Seems like we have to live with it for a while...
It is being used in much more than just telecom and cryptography. Even the UPU use it for tracking packages that get shipped. Take a look at Space Link Extension (for space communications) that uses ASN.1 also.
