I have pondered a long time whether to learn web programming for my customers' services app, so that they can access their user & device statistics, crash logs, manage service messages, push messages, etc.
I now have decided not to pursue this path. Web technology is a mess, even more than mobile technology. It's lacking a clear separation of layers and although many frameworks nowadays are using MVC or similar patterns, I feel I have to do too many things at once (web service, html templating, css design, java script for interactive stuff, etc.) to really make a professional web app.
I'm going to make a mobile client instead, using the technologies I already have mastered and in which I'm productive. Yes, I still want to learn something new, that's why I'm working with a NoSQL database now for the first time.
Of course the downside is my customers can no longer use their web browsers to manage all that, but since they have their iPhones and iPads always around anyways, I'm sure they can cope with that.