Since almost one year I’m involved in Alfresco ECM huge architectures design, and considering my expertise in open source communities, I’m now at the level of being able to give a clear statement on which are the aspects (not in the Alfresco meaning 
in which this GREAT product still lacks, especially in terms of open source maturity and scalable community / enterprise application lifecycle support.
My past experiences with open source communities and frameworks like Apache Cocoon , recently released 2.2 version with features like complete springification but most important (to me) the full m10n (mavenization, from Apache Maven), taught me that even the most genius idea, the best architectural pattern or the killer app, will NOT have the desired penetration and adoption (and expected ROI, if you think about enterprise backed open source) if not properly backed by a solid foundation which can (at least) provide the following high level features (among many others which I consider as derivatives):
- Easy inter-component and intra-component reuse gearing best practices
- Centralized and standardized component management and definition
- Fast project startup and (fast if not “hot”) develop-test-commit cycle
