honestly apps for tablets can be much more important... but they have to go way beyong just a stream lined web exp. if ure just going to make a magazine app and ure big draw is showing the page turn, of course its value is ery limited.
but if u can personalize the experience in such a way to make it unique to the user, display fluid content, then u can create lots and lots more value than in smart phones.
right now smartphone apps are a need because their brower sux and its just cumbersome to interact with a full website with the tiny screen.
tablets fix the small screen issue and interaction (to a degree of how much compatibility exists with tablet browser) so tablets dont exactly need apps now... however going forward tablets allow for more processing power in general and more unique expiriences.
one quick idea i can come up with is a fandango app on the touchpad... check out ure movie decide u want to see it. it searches for theaters and times around u. u choose where and when, pay, and when ure ready to leave u can touch to share ure ticket stub to ure pre3.
of course this can be done via email as well, but with TTS it will be a more seamless exp.
If webos take off, the ecosystem story will grow exponentially.