I think the majority of creative or power user applications will be for those with a complex control surface, such as the examples above. The large touch interface of the iPad is much simpler to use than a traditional mouse keyboard. Also when compared to Wacom drawing tablets http://www.google.com/products/catalog?hl=en&rlz=1G1GGLQ... it is competitive, at the iPad low end the iPad is about $200 more, though not quite as functional, the iPad does not have pressure or stylus tilt sensitivity but it is portable. If you are interested in developing these types of applications you have to have one. If you do not have one you will never see were the deficiencies are or know which problems to solve. The device as only been available for 10 days. I would expect it will take a year or two before the application space has been adequately sampled.
Another obvious short coming, or opportunity, is with file synchronization and management. I am currently using dropbox, https://www.dropbox.com/ with ReaddleDocs http://readdle.com/products/readdledocs, which works for reading. If documents are generated on the IPad you have to use iTunes, eMail or an application specific server for document synchronization. Neither of these is adequate.
The typing problem you mentioned can be solved by a case that holds it an an angle, such as http://www.goincase.com/products/detail/CL57512. The number of viewing and use positions for the device is greater than that for a laptop. Also heavy duty typing can be handled with a bluetooth attached keyboard though for my needs the the onscreen keyboard has been adequate.