Yup, Titanium works for iPad apps. Like Dave said above, there are some (two to be exact, as of today) iPad specific API's, other than those you would just use all the other existing APIs and when you create your project in Titanium Developer, you would choose iPad as the project type.
The API documentation (linked to the iPad specific APIs but the list on the left has all available ones for Mobile Dev):
http://developer.appcelerator.com/apidoc/mobile/latest/Titanium.UI.iPad-module
To get an idea of what you can do, take a look at the Kitchen Sink Apps. There are two, one for the iPad, which is basic and really only shows the iPad specific API usage for the most part. The other is for the iPhone which has nearly every available API on display. They are ugly apps but they do the job of showing you what's possible and give some decent reference code. You can find the kitchen sink apps on Git hub (link below) and go here (http://developer.appcelerator.com/doc/kitchensink) to see how to run them in them the simulator (requires xCode which is free from Apple).
Also, you can find some showcased iPad apps built with titanium on the Appcelerator website (link Below), just search the page for the word iPad.
Kitchen Sink Apps : github.com/appcelerator/KitchenSink
Appcelerator Showcase : appcelerator.com/showcase/applications-showcase/
(sorry for the non linked URLs but Github will not let you post more than one link unless you have more than 10 reputation points)