Hi. I faced the same thing. I’m a total noob with WP, so take the following with that in mind please. What I did was….
I simply moved the ‘wordpress’ directory (including its subdirs) up one level, so that it was sitting in the domain root. I’m not certain, but I probably also edited the existing index.php so that it pointed to the correct folder (basically the reverse of the instructions on the page you linked to.)
This worked, but I found that I only had the option to have blogs in subdomains, not in sub directories. Not sure why; there was also a problem with how WP constructed the site paths, something to do with my blog being “more than 1-month old,” which made them go 404 every time (I posted about this within the last few days.)
What I eneded up doing was taking a backup/export of the entries etc (in the Tools menu), and then doing a totally fresh install with an empty database. Once I did that, everything worked.
HTH
Well, I pretty much tried to undo the things I did in the above link, and things seem to be working ok except for one thing.
The plugin “Fast and Secure Contact Form” now does not show the CAPTCHA images on the contact form. I’m doing a little digging and will report back if/when I figure something out…
Thanks for your help, ND.
After poking around a bit I wound up just reinstalling from scratch and decided not to worry about the multisite feature in 3.0 for now.