I think it would be great if there was a version of Luke that always worked with trunk - and it would also be great if it was easier to match Luke jars with Lucene versions.
While I'd like to get GWT Luke into the mix as well, I think the easiest starting point is to straight port Luke to another UI toolkit before abstracting out DTO objects that both GWT Luke and Pivot Luke could share.
I've started slowly converting Luke's use of thinlet to Apache Pivot. I haven't/don't have a lot of time for this at the moment, but I've plugged away here and there over the past work or two. There is still a lot to do.