I know the guys speak germish :-). I found this video quiet interesting as it explains how Solr works and how you can use it with/for your application. In this case it`s the TYPO3 cms but it could also be a forum. Somewhere Wayne Luke mentions that Solr requires a dedicated server and so it can´t be the primary search solution for vB. I agree but vB should definately support it as an option so user permissions are taken into account etc..
Just imagine how great it would be to search for a rather unspecific keyword and then you can click through the filters for tags* subforums* authors etc. and narrow your search very intuitive. Absolutely user friendly and very fast. Would be an enormous benefit for every big forum.