I think people looking to 'replace' twitter with this are going to struggle because it's not trying to really accomplish the same things, and you don't have to restrict yourself to the format of glib microblogging style for every kind of post you would otherwise like to make, nor do you have to think about metrics or making it easy or hard to find your important posts because you can use the tag system to create hyperspecific ones if need be, etc.
If anything this is a bit more like a Tumblr without the visible metrics incentivizing certain attention-seeking behaviors. This site doesn't need to be the one-stop-shop for all forms of posting, either. It was nice when Twitter was just a supplemental thing, for example.
