I've done this in a VPC on a single server farm with tutorials I found on google, and I've written various AJAX WebParts for use with sharepoint inside that VPC.  I'm looking now for some examples of how people have use this on production systems and if they've had any headaches or problems with any Use Case Scenarios when dealing with SharePoint after its been AJAX enabled.  Does all of SharePoint different built in features accept AJAX enabling?  I know that there's been talk about Microsoft putting AJAX enabling into SP1, has anyone heard any confirmation of this?

 The answer is Yes! However, none of the already existing content of sharepoint is AJAX enabled, but SharePoint after SP1 is installed and configured will accept new controls that are AJAX enabled! 

 Can't wait for 2009 version which may have AJAX enabling for the entire SharePoint site!  Can we say "Enhanced End User Experience"?  I think you can!  Of course this is just my guess that they will have it out by then...  ;)