Just found out that there is a program called NinjaKit out there which gives full support for Greasemonkey scripts in Safari. I have installed it along with all of my regular GM scripts, and so far everything seems to work great. For developers, it also allows you to edit the scripts in the browser directly and save it - makes updating pretty easy.
I just started using it, so there could still be issues, but so far everything seems great. Just wanted to let Safari users know that there are options for you.