I have a couple of other suggested enhancements. BTW, copying the default.aspx to desktopdefault.aspx did the trick. Works great!
1. Allow a user to link to another wiki page on another wiki. Ie. Say one wiki for 'Sales Team' has a link to 'DotNetNuke' wiki page. The page, say, describes DotNetNuke and includes a link to this site. It would be nice if there were a way to be able to have ONE 'DotNetNuke' link to a wiki page on, say, the 'IT Team Wiki', and have it point to the Wiki page on the 'Sales Team' wiki, instead of having to copy and paste the whole page and any sub-pages.
2. The back button issue really messes with navigation. There really needs to be something in the 'administrator settings' or wiki settings that allows the back button to work. Using the 'security excuse' just doesn't make it...especially since any administrator should be logging out. IMO, that's just an excuse to not have to implement the extra work it would require to make the back button work. 'Yeah, let's just say it's a security issue! That's the ticket!'. 
Seriously, if someone on the core team things it's such a security issue as opposed to a 'more work for us to do issue', they could poll users. I guarantee 99% of DNN users would want the back button to work. If there are people that have 'security issues' with it, then either the back button should *never* work, or much smarter, it should be a checkbox, and made the choice of users. For a Wiki navigation it's a show-stopper, IMO.
3. Add an in-line editor, and AJAX, instead of using the FCK editor (or any other editor). Just adding this feature and the backbutton working, would turn this into a world class Wiki, IMO. It ain't that far from it now.
4. Add the ability to have plug-ins. I know there's a menu item for it, but it doesn't do anything that I can see, and there's no documentation I can see for it either. I bet a lot of people (definitely at least me), would start adding plug-ins. Even better, why not inspect one or two of the most popular wikis, and make plug-ins so they're compatible with these popular wiki plugins--that way, you'd instantly have a wealth of plugins available.
5. (Yeah, it's gettin to be a long list...I was thinkin' while I was creating all these wikis for our company site. ). Makle it an option to have the menu at the bottom of the page and/or at the top or sides of the page. It's sort of a pain when a page is long to have to page down a couple of times to access the menu. It would be even cooler to make the menu so it 'slides' on the side, like a pop-out menu I've written at one time and seen in many places.
Okay, that's it for ideas. Good job Chris and company. This wiki could really turn out to be a killer ap for DNN. Okay, one more idea. Imagine if one could *replace* the default editor, with the Wiki, using an inline/AJAX editor. So *any* content would be 'wiki'able. Think about it. You already have version/content management in place, and you could create a checkbox to turn on/off wiki capabilities. Now that would be really cool. All of a sudden, articles and any other modules could have wiki capabilities. And heck, if you added email notifications, well, fahgedaboudit. You'd be considered gods. :)