If you are looking for an application that allows you to manage your Netflix queue with Mac style, then iNeedFlix might be for you. iNeedFlix allows you to (as long as you are signed into Netflix through Safari) manage your queue. You can both move and delete items in the list. iNeedFlix interfaces directly with the Netflix server, so changes will be made almost instantly. This is a very simple application for a very simple problem, however, it would be better if you could be signed into Netflix through any browser, not just Safari -- or have this step eliminated completely.
If you are looking for a Netflix application for the Mac that is a little more full featured, then look no further than Netflix Freak.
You can download iNeedFlix for free from the developer's website or from VersionTracker.