Would be great to see these in the tree since these haven't been updated in a while.
There is an ebuild for slot 2.9 in "seden" overlay: http://gpo.zugaina.org/dev-java/lucene-analyzers
It holds some more java-related ebuilds as well, including stuff necessary to build eclipse-3.7.* for example.
I've just compiled lucene-analyzers-2.9.4 from seden without any problems on amd64.