On the mailing list, Greg Ward mentioned that caching annotations will be 
especially useful with the more accurate algorithm mentioned here [1].

If this algorithm was implemented in the annotate command, would there be 
interest to integrate the annotation caching code (see [1]) in Mercurial core? 
Alternatively, this could be made part of the cache-annotations extension.


[1] http://selenic.com/pipermail/mercurial-devel/2010-January/018304.html