results should be clear(and suitable for scripting) about the type of each hit

[Chris Jones]

I think it is quite likely in a large/old tree that search will find a lot of results and depending on what you are looking for, results from either commit messages or the revisions themselves may not be wanted.
I think it would be nice if the output format of the results could clearly indicate the source of the result, e.g.:

bzr search foo
Revision 123 Commit message: Changed frobnosticator to use super foo powers
Revision 123 Summary: superfoo(baz)

[Robert Collins (lifeless)]

This does affect usability. If you're interested in sending in a patch that makes it look like you would like that would be wonderful. The code to change is the 'document_name' method on the various Hit objects in index.py.