It's been promised for Q1 2008, so should be released very soon. I wouldn't use it for a critical site until it's been in the wild for a few months and a couple of revisions have been released. You will also struggle to find decent templates for it until there it has enough of a userbase to make it worth professional template creators doing anything for it. If you are going to take your time building your site, it may be worth giving it a go, but if you plan to launch your site in the next couple of months or so I'd use something else.

Yes you can make it work on a PC, though you'll probably have to dual boot Windows with Linux/*BSD to do it.

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Lawrence