And before we get a bunch of people stating that "nobody really knows" what happened to the Dwemer, http://imperial-library.info/content/final-report-trebonius is your friend. If it doesn't convince you, likely nothing will.
I agree. This explains the Dwemer motivation for using the heart, their philosophy, what they hoped to gain, etc. However, it doesn't actually say what happened to them. It explains what their goal was, then poof. We don't know if they succeeded, failed, or anti-failed.
Since most of the individuals that tapped into the heart basically got what they wanted though, I would assume it safe to say that they unmade themselves, a success! Except for Yagrum . . .