First, you should not jump into patterns as a mechanism to replace a sound methodology and a sound process. Instead, patterns are able to become part of each, and in many instances there is already some pattern-oriented software architecture in place. Patterns simply formalize the process, filling in the gaps and providing a consistent approach. I've heard some compelling talks describing patterns as the Second Coming of software architecture. However, I've seen no evidence to validate those assertions.
Patterns are simply another tool at our disposal.
Second, patterns only add value if they are practiced consistently over time. Just capturing patterns for one application is hardly worth the trouble. Application architects must establish the infrastructure for patterns, creating standard mechanisms to capture and maintain the patterns over the long haul, refining patterns when necessary. For instance, the vocabulary should be the same across many projects, or there is no need to create a standard vocabulary. Consistency is key.