After waiting, patiently, to the point of impatience and just plain weary of the journey we have been working on a transition to iCal and iCal server. After years of NUTD use we have data that needs to move to iCal/Server. This is what I have found and it works... to a degree. Probably as good as any other known solution. I would love to hear of a better one as well as use it... we are only in the iCal Server testing phase but this is about as close as we get jumping the hurdle in question here.
The steps work and it does indeed port your NUTD data into iCal. The problem being is that it does not port over, in regards to meetings, those invited nor their response. What it does provide is the transfer of all scheduled events. Details? not so much but it is better then starting with a blank slate. Anyways here are the steps...

Export your calendar as a text file from Now Up-To-Date with Export Template 'Calendar Archive' and the following settings:

Item 1: Date
Item 2: Start Time
Item 3: End time
Item 4: Title
Items 5-10: "None"

Import your calendar into Palm Desktop v. 4.2 (free download at with these settings:

Fields: Now-Up-To-Date
Delimeters: Tab & Return

Export your calendar from Palm Desktop in vCal format.
Import the vCal formatted file into iCal.

This information was originally provided as a "How to" sync your NUTD incompatible PDA/phone with NUTD. I have modified it slightly to do what is stated here.
Hope it helps and by all means I encourage you all to post your methods and conclusions if you decide to go the route of iCal.