First of all, no other tablet maker will do well against iPad with ARM based processors.
But the ultrabook can create less of a need for tablets altogether provided that the difference between one with a convertible touch screen tablet capability costs around $200 more than one without. People over time will want the best of all worlds. Apple's apps, Google's apps, and Windows full capabilities.
A one time ownership of an Apple smartphone is good enough for enjoyment of Apple's apps for the most part. No real need to upgrade a smartphone. Just use the wifi capabilities until the phone breaks.
Second, many should be looking for the vast selection of Android based smartphones to get access to the many perks that Google will provide for daily useage. Finally, an ultrabook with Windows 8 software should rap up the experience of mobility by having a fully functional sleek and lightweight laptop with conversion to a tablet that has the main functions that can be satisfied through only touch capabilities. As Apple said, with over 250,000 total apps available, the average user has about 106 total apps. So Microsoft could easily satisfy most of its customer based with around 10,000 of the most popular apps. Most of Apple's apps seem very childish and hardly ever used. Or used once to try it out and placed in permanent storage if not totally discarded.
This will be key for ultrabook's success and I think Intel knows this along with its partners.
The most successful tablet maker second to Apple is Samsung. Same company that build tablets for Apple. Yet they still only have 2.4 million quarterly sales. This pales in comparison to the number 5 PC seller, Acer, which sells over 6 million unit in a quarter.
The ARM tablet market is definitely going to be affected by the price points of Ultrabooks and laptops. For near the price of a spendy Apple tablet or perhaps even less you can now buy a functional computer in Ultrabook or laptop form. And more form factors are on the way. Why buy such a limited product when you can get so much more value and use?
I want to see the commercials for the convertibles rammed down our throat like they are doing right now with the available Ultrabooks. I think the tide will start to turn once they mass market these and people begin to see that they can get EVERYTHING they need all in one purchase. A slender, solid laptop with touchscreen. The next generation will all be carrying them.