What remains to be seen is whether German cycle sport (Kohl is I think Austrian, but the team is German) can survive this blow, after a series of high profile doping positives over the last couple of years.
Schumacher's defence team apear to be taking the traditional aproach of trying to rubbish both the testing lab and the test, and identifying procedural flaws. Unfortunately for them, the test was developed in collaboration with the company that developed CERA, and is pretty likely to be as watertight as these things can be.
[update 14/10/08 - cyclingnews.com reports Kohl's B test also positive for CERA, so I guess he's positive, not "non-negative". A later report from cyclingnews.com suggests the second positive is actually a separate A sample - so double "non-negative" rather than positive]