It wasn’t that long ago when electronic communication was limited to telephone calls. You picked up a telephone receiver, pressed a finger down on a series of numbered buttons, and voila, you were able to speak with someone miles away.
Sometime in the 1980’s we added email to our bag of communications tricks. Since then we’ve expanded to video, instant message, WebRTC, and SMS text. I would be remiss if I didn’t add Facebook, Pinterest, Reddit, Twitter, and other forms of social media to that list. There are days when I feel I communicate more through these new forms of engagement than anything else.
My latest article for No Jitter explores one way to translate old fashioned telephone numbers into SIP URIs to create a cohesive web of communications.
Tao, Zen, and Tomorrow 
The ENUM is definitely not obsolete. You can find ENUM in plenty of mobile networks (I’d think that majority of VoLTE/VoWifi deployments rely on ENUM). It’s being used for routing (e.g. RFC4769) and very much for Mobile Number Portability.
The disappointment connected to ENUM is not related to technology itself (DNS still rulez :)) but to expectations that there will be an open public ENUM database, which would allow to route the calls based on (actual) users preferences and capabilities (e.g. to prefer free VoIP routing).
Thanks! Would you mind posting that on the No Jitter version of the article? That would help get the word out.