>Please help me retire this dinosaur.

actually its not the old dinosaur that one thinks it is - ( it is the fastest of the dnn frameworks) there are still a lot of dnn2 sites out there and there are still a large number of modules available

However to update from dnn2 to dnn3 I would strongly suggest that you do it on the inhouse computer rather then online. When I updated my clients I found that I had to go from dnn2.2.1 to 310 ,335 to 337 this gave me an update with no errors - again however it does not update your users tables  suggest you use non encription on the passwords in the dnn3 web.config.this allows you to manually enter the users into the database or there is a desktop program that will I believe move dnn2 users to dnn3.

If you try to update from dnn2 start to dnn3 then the install can have problems in the sql scripts or at worse not notify you of errors in the scripts and you end up getting errors at inconvierent times after the update. if you have custom dnn2 modules and who has not then you must update them to dnn3 -your skin files will need some minor changes also

ie Inherits="DotNetNuke.UI.Skins.Skin" instead of Inherits="DotNetNuke.Skin" the container files will also need changing

Custom modules can be changed quite simply if you have the code -

if you do this offline then once any errors are corrected you can upload the lot to the new server without any down time.