>However, a key aspect of log analysis is to understand the format of the arriving log data, especially in a heterogeneous environment where different applications may be developed using different log formats and network protocols to send these log data.

This is exactly what we are trying to solve with Fluentd, an open source log collector with the goal of unifying log management (http://www.fluentd.org/blog/unified-logging-layer) Syslog is a solid, "tried and true" tool, but when it comes to extensibility/modularity, it is definitely lacking.