I don't think Steve Jobs will be overly worried about third party tablets. After all, the iPhone pricepoint has hardly moved in 2 years despite potential iPhone beaters in the Samsung Galaxy S and other HTC offerings.

What Apple have done is quite clever and made users "aspire" or at least feel like they're "aspiring" to getting an iPhone/pad. Not only that but in my humble opinion, iOS is far superior in many ways to the relative new kid on the block Android.

A phenomenon was present with the PSP3 and the Wii: The Wii was cheaper by a long shot but due to Nintendos shipping policy, the Wii was a rare beast to find in its early days in the UK, making it extremely desirable and hence driving its meteoric rise to stardom (as well as being a unique way to play). To this day the Wii hasn't changed much in value, whereas the PSP3 has dropped considerably.

Apple stopped other parties from manufacturing apple products a number of years ago and Umax were one of the last licensed companies where you could get a "mac" that wasn't made by Apple. This, and the fact that they then also focussed on just the Mac and shelved their tablets (think Apple Newton) allowed them to really pull out the stops in making the desirable macbooks mac minis and new iMacs as well as iPod, iPhone etc.

Today the Apple products are not simply about featureset, its about a quality, feel, aethetically pleasing, intuitive interface objects of desire.

Even after the iPhone4 aerial-gate debacle which Jobs shrugged off saying something like "use the other hand when calling" possibly shows that they don't think that the competition can dent their market share.

How the mighty might fall being guilty of too much confidence in an ever more competitive marketplace. Time will tell.