So I shared a talking slot with Ninh Bui from Phusion, and we merged our slides into one large Keynote file with speaker's commentary included. You can download the slides here:

http://ninh.nl/rubyonosx.key.zip

We made some good points IMHO, not sure if I could convince the crowd though. ;)

By popular request ;), here is the PDF exported version of the slides:

http://www.raschke.de/julian/temp/rubyonosx.pdf

Unfortunately, some of the slides got mangled by the export. The commentary is also not what we actually said, but should get the rough idea across.

Speaking of conferences, there seems to have been an unrelated talk at Euroko about Gosu :)

http://app.euruko2009.org/talks/9-fun-with-ruby-and-without-r-s-program-your-own-games-with-gosu

My short talk had a strong emphasis on how Ruby is suddenly more than a boring glue language when you start writing games, so the slides by Javier Randrez actually go into a lot more detail about what Gosu can do.