So here is an update on https://bugzilla.novell.com/show_bug.cgi?id=625677. After contacting the author about the spelling suggestion issue I was having, I finally got it to work. As an added bonus, I have discovered and enabled the related articles feature as well. With these features working, Lucene is definitely a better option than Sphinx now.
All the "new" wikis on stage (en, dewiki, and languages) are now using Lucene search. The enstage wiki has the most content of the three, so you can get the best idea of how well it works by going there. However, those of you who are fluent in German should also try dewiki, so that you can see how well the search deals with German stemming and stopwords.
The indexing takes 45-50 seconds on stage, so I'm expecting it to take about a minute to index the live English wiki, and probably another 30 seconds for the production dewiki and languages. Once everything is transitioned over to the new wiki structure, total indexing will probably be in the 10 minute range. I plan to put the indexer on a daily cron, so all changes should show up in the search within 24 hours.
I am setting up a meeting with the data center to go over an OS upgrade plan so that we can get this going as soon as possible.