I'd have to agree with iqster in that it doesn't seem to be burn-out as much as doing something new. He doesn't seem to talk much about the symptoms listed at http://jacquesmattheij.com/Are+you+suffering+from+burn-out although he said he has them (even "if [he] didn't know" it?). Not that I doubt his story or anything, but he seemed motivated enough to build new things and not sulk in depression (symptom #10).

"When you're burned out change, do something that is as far away from what you were doing when you were burned out."

I guess this means he defines being burned out as tired of what you are currently doing, and not burning out on doing something productive altogether. In that case, he's probably right in saying that you should change when you're burned out.