At least for me it’s turning into infrastructure more and more lately. And i guess this is true for more people. And twitter doesn’t like it, so that’s why they announced their API changes. But people don’t like it, because Twitter is infrastructure…
I hardly use the twitter app or their website. Mostly i use it in Zite, to find interesting articles to read, and to promote articles i like. And also in instapaper and Pocket.
Twitter is the infrastructure that enables these apps to display great content. Replacing twitter with Google+ or app.net shouldn’t be too hard…