When Steve Jobs launched the first iPad in 2010, he did so against a backdrop of uncertainty.
Its arrival came with the typical, predictable fanfare: Apple devotees queued around the block to get their hands on it, while technology blogs and news websites - including this one - prodded excitedly at it.
"Is this the future of computing?" everyone wondered. Back then, nobody really knew the answer.
It was a mood best summed up by a simple remark from BBC website reader Ian Mears.
"I must admit I want one," he wrote. "But I don't know what I'd actually do with it."
Yet the numbers do not lie. Two years, and over 50 million units later, Apple can rightly claim to be king of the tablet market.
But as Apple chief executive Tim Cook launched the new iPad, he did so facing a different kind of uncertainty.
Today's doubts centre on whether the Apple's device can remain at the top of the tablet tree.
Judging by the reaction of the technology watchers at the London media event, Apple has done just enough - for now.
"I think they've done a good job to give first-generation iPad owners a reason to upgrade," says Carolina Milanesi, lead Apple analyst for Gartner.
"And also to all the people who felt a little less cool now than they did an hour and a half ago. That's what Apple does."
Aside from the unsurprising addition of the "retina" high-quality display, of particular interest was the addition of 4G LTE technology: a method of receiving data far faster than the iPad's existing 3G capabilities.
Windows 8's Metro user interface has won praise from many reviewers
But for buyers in the UK, this speed boost remains out of reach. The country's telecoms regulator Ofcom is still planning a 4G mobile spectrum auction. By the time the networks roll-out next year, the next iPad may have been unveiled.
Despite the frustrations this may cause to some UK owners, Ms Milanesi predicts that it will not prove too damaging to sales.
"If it was at a higher price people might have said 'why bother'," she says.
"Most people will still use their own wi-fi, and although we're not going to see LTE, they have optimised HSDPA [an enhanced 3G protocol]. So even to a UK consumer, it should see some improvement."
At present, most of the iPad's competitors come in the form of Google Android-powered devices, mainly from Samsung and Motorola.
Mr Cook attempted to deal with this head on, with a cockiness designed to delight the Apple-watchers in attendance, while also antagonising the creators (and perhaps the owners) of the Samsung Galaxy Tab.
Reeling through apps such as Twitter on the Samsung device, Mr Cook claimed to have demonstrated the inferiority of his rival.
“The low-end is owned by Amazon and the enterprise market will soon be owned by Microsoft with Windows 8”
It is no coincidence, some would say, that this show of bravado comes at a time when Apple and Samsung remain locked in ongoing patent legal battles.
Nevertheless, even one of Samsung's product strategy managers recently admitted "honestly, we're not doing very well in the tablet market", according to a recent Cnet report.
Even so, experts are keeping a close eye on the Galaxy Note, which is sized somewhere between a tablet and a smartphone.
The firm has already shipped more than two million units. While not all of those will equate to sales, the figure is considerably better than some doubters predicted. The South Korean firm is targeting 10 million shipments by the end of the year.
But turning back to tablets, one company that may pose more of a challenge is Apple's long-time rival Microsoft.
The firm enjoyed a high-profile and well-received launch for the preview of its Windows 8 operating system last week. The system will offer users the same functionality on their PC and tablets.
Samsung competes with Apple while remaining one of its key suppliers
"Come Christmas time, the big battle in the consumer space will be Microsoft versus Apple, with Google pushed to the side," predicts Stuart Miles of Pocket-lint.
Gartner's Ms Milanesi agrees, saying that the multi-platform Windows 8 operating system will have Apple looking over its shoulder.
"I do think that overall Microsoft is going to be a more serious contender than Android, simply because I still don't understand what Google wants to achieve.
"Their focus around revenue coming from advertising takes them away from caring about the device, the experience and what comes with it."
However, it may be too early to write Android's prospects off.
The operating system already accounts for nearly 50% of the US smartphone market, according to a recent study by Comscore.
Time magazine and Wired have reported rumours that a Google-branded seven inch tablet may launch later this year running the new Ice Cream Sandwich version of the software and undercutting the iPad in price, offering the firm a fresh opportunity to appeal to owners of phones using its system.
Amazon's Kindle Fire appears to have proved that there is an appetite for a budget-priced tablet.
The firm has not released detailed sales figures, but analysts at iSuppli have estimated that it shipped 3.9 million devices in the US over the last quarter of 2011, accounting for a 14.3% share of the market. If accurate, that would make it the sector's second biggest player behind Apple.
Whether it will prove vulnerable to the discounted iPad 2, which remains on sale, remains to be seen.
The most exposed company may prove to be Canada's Research in Motion (RIM).
Amazon has not revealed when it will start selling the Kindle Fire in Europe
The firm recently released version 2.0 of its Blackberry Playbook software, providing fully-functional email, contacts and calendar apps that its tablet previously lacked. It also offers users the opportunity to run Android software, radically extending the amount of programs available.
But some analysts fear the company may still struggle to ignite interest, and predict more bad news when it releases its next results on 29 March.
"Apple may sell more of the new iPads in two days than RIM will have sold Playbooks over the whole of its fourth quarter," says Colin Gillis, senior technology analyst at BGC Partners in New York.
"It's possible that the firm may have even had more returns than sales. They lost the high-end to Apple, the low-end is owned by Amazon and the enterprise market will soon be owned by Microsoft with Windows 8."