there's a module to get mySQL to work with in WO. I've used it myself and it works fairly well though it is a work in progress. I think its opensource and you can find it on http://www.stepwise
there will most definitely be a way to get mySQL - WO -OS X working together. It mostly depends on Apple releasing WO for MacOS X for real (apart from user hacks). If Apple just recompiled WO4.5 for MacOS X I would instantly move all development to MacOS X PB, beta or not.