More resources:
http://photoshopnews.com/2006/07/20/lightroom-resources-updated-2/
p?tr??k, for the moment, the Windows build is indeed, not so optimized for speed. but it allows you already to experiment that new workflow. Anyways, I would not recommend using a beta program for important stuff, rather to use it on copies of your files.
I'm sure that with the Engineers (*) that are working on Adobe Lightroom, it will become a must have tool that will fit the fotographer's workflow. I recommend to read the very first tutorials on lightroom mac, as they explain the basics, and working with lightroom will become more intuitive...
(*) Thomas Knoll, creator of Photoshop and ACR
Mark Hamburg, the second most important engineer/architect of Photoshop
Zalman Stern, who helped convert Photoshop 2.5 to Power PC code on the mac side
the famous Seetharaman Narayanan
Phil Clevenger, a former KPT UI designer (the one that came with the nice ideas, not the obscure hidden interface toys
former Pixmantec Engineers, Tang Laerke and Michael Jonsson, that also created Capture One, who will work on the engine of Lightroom, Adobe Camera Raw
And many other talented folks who came from different teams at Adobe and former Macromedia.
Lightroom, like Photoshop will also be able to evolve thanks to modules (plug-ins) and that was a key part of the success of Photoshop.
So, do look at lightroom as a work in progress, and DO give feedback in the official Adobe forums (labs.adobe.com)
