building OSGi applications

In the recent days, I've seen an increasing amount of interest in building solutions for applications made up of OSGi bundles. So far I was a true believer, that OSGi and bundles will not play a big part in Enterprise Java. But who knows? If you try to develop your own OSGi Application at the moment, you come across several problems.
An article from Rob Harrop discusses some of them and point out the main challanges to face.