WebOS 2.0 brings enhancements to universal search, card (i.e visible running applications) organization, customizable text auto-completion, different touchstone screen states, and many minor feature additions such as Bluetooth keyboard and VPN support. Just Type (formerly known as universal search) adds support for searching application indexes (such as email), Google suggestions, and more search engines with the option to add any website that WebOS detects as search-compatible. Just Type also provides quick access to updating a Facebook status, posting to Twitter, and creating a new note, memo, or email.
Text Assist wraps support for auto-capitalization, auto-correction, and user customizable shortcuts (similar to Palm OS). Exhibition provides for customization of the Palm screen while the device is on the Touchstone.
Arguably the most touch tablet friendly feature is the card interface, and the addition of stacks provide an organization method that is not only useful on small screen but large screens as well. On a device with a 3.1" screen like the Palm Pre or even a 2.63" screen like the Palm Pixi, using stacks makes having 10+ cards open simultaneously a lot more manageable. When one card opens up a web page or email card, for example, the cards are automatically stacked, and moving a card into or out of a stack functions the same way as re-arranging cards in WebOS 1.x. The following video is a good demonstration of how stacking cards looks and works.
On a WebOS tablet, I anticipate that stacks will actually appear expanded when in view so that multiple cards can be used simultaneously. The Notion Ink Adam can display three Android applications on their 10.1" 1024x600 screen and also support applications with split views or full screen apps, but scrolling between applications can be cumbersome without a method to group applications into mini-workspaces.
One of the more exciting things in development at HP Palm is the follow-up to the Palm Ares SDK, the Palm Enyo SDK. HP Palm is working not only to improve performance of the Webkit engine to work on memory starved devices such as the original Palm Pre and the Palm Pixi but also provide a basis for applications that can easily expand to being used on larger screens. Palm demonstrated a mail application that, running on a mobile showed only one screen at a time, but when running on a larger screen showed three panes simultaneously. This also parallels windowed vs. full screen applications on a desktop; on a tablet, an application like mail could either be placed on one pane or expand to three panes based on user preference. The following is a technology demonstration of Palm Enyo.
The Bluetooth keyboard support will be useful when coupled with a touchstone accessory that could be used with a WebOS 2.0 device with a larger screen, such as a PalmPad or a phone with an HDMI out to an external screen. A Wacom-like stylus would also be slick and is a possibility thanks to HP.
One feature that I would love to see on WebOS tablet (and phone) is a screen of widgets similar to the Dashboard feature on Mac OS X. I prefer not to clutter the desktop like Android tends to, but having a screen that can be summoned in or out via gesture would be useful. At the moment the notifications section already provide me with the current temperature and is a good location for small snippets of information, and Exhibition will be good for providing access to news headlines and more weather information, so Palm WebOS is not totally lacking on that front.
So to wrap-up, expectations are very high for the WebOS tablet, but the UI enhancements brought to WebOS 2.0 can be expanded to bring an excellent tablet experience that should knock Notion Ink's Adam, RIM's Playbook, and Google's Android Honeycomb out of the water. In the meantime, enjoy video demos from Notion Ink, RIM, and Google and be sure to check out Palm's former UI designer (now working on Honeycomb) Matias Duarte interview on Engadget.