I just have discovered an online publication, called Journal of Object Technology (JOT) and published six times per year by the ETH Swiss Federal Institute of Technology, that has lots of excellent articles.

The mission of JOT is to present its readers with timely, well-written, and interesting state-of-the-art papers and special features (columns, book reviews, software reviews) dealing with every aspect of object technology both theoretical and practical. Topics include OOA, OOD, patterns, OODBMS, OO languages, components and case studies. The columns, both guest and regular, are written by recognized specialists and experts in the field.

(Via Hacia la Cuarta Generación del Software – in Spanish)