I too used the free version of TripIt and Worldmate. In the end, I settled on Tripit, because:
1) Tripit allows more control of notification emails. Worldmate sends confirmation emails for every new addition, which seemed goofy since things only get added when I add them.
2) Tripit lets you move or copy items from one itinerary to another, while Worldmate does not. This is an because both programs occassionally put stuff in the wrong itinerary.
3) While WorldMate has an application for WinMo (my platform), it frequently crashed my phone.
4) Worldmate provides no way to display itineraries in Outlook unless you the use Blackberry version. Tripit provides a calendar feed, which is not perfect, but better than nothing
5) Worldmate showed consistently inaccurate weather forecasts, and would not automatically show weather for my current location (TripIt does).
6) Tripit offered a year's subscription for $49, versus $129 for WorldMate