According to MacRumors, iTunes may updated to version 9.1 next month, presumable around April 3, the same time as iPad's U.S. launch this Saturday. Definitely the new version will contain iPad support claimed by the rumors:

According to the source, the existing “Audiobooks” entry in the iTunes Source list will be replaced with a broader “Books” section. A similar change will made to the sources for managing content on connected devices such as iPhones, iPods, and iPads. The revamped “Books” section for connected devices will reportedly display all book content compatible with a given device for easy content management.

New features in iTunes 9.1 are support expected growth in eBook content driven by the iPad, and Audiobooks entry in the iTunes Source list will be replaced with a broader Books section. It also bring enhancements to the Genius Mixes capable to automatically selects songs that "go great together". Weaked summary panes (including a move of the “Check for Update” and “Restore” buttons to the left side of the pane), and automatically convert songs to 128 kbps AAC format when syncing to devices.