There are lots of challenges to building electronics into clothing, but perhaps chief among them is the problem of getting durable wiring onto (or into) fabrics. The Economist has an excellent article about who’s doing what to solve that problem; it’s a rare must-read and must-clip if this is a problem that’s important to you.
In fairness, the article may be a little ahead of the state of the actual art. The industry group in this area, the Conductive Fiber Manufacturing Council, appears to be small with a limited membership. But the group includes academic and research developers, and there’s lots of activity at that level. It’s worth keeping an eye on, even though the immediate applications are limited.