Alex has started two Oracle security blogs. The first in in English, the blog is titled "Oracle Security Blog" the second is a translation (actually its more than likely that the English is a translation of the German blog) and is in German and is titled "Oracle security blog (dt.) - Blog zum Thema Oracle Sicherheit". Both blogs have been added to my Oracle blogs aggregator
so watch out for them there as well.
One of the posts is about the new Oracle security videos that Alex has added to his site. These videos include using nmap against an application server, some password cracking, Oracles default password tool, a demo of MatrixAy (which is excellent BTW) and more...
These are excellent videos and worth a look.