In the year since CES attendees named tablets the “must-have” technology of 2011, hardware developers have learned one major lesson to distinguish their products: It’s not enough to copy Apple’s iPad.

With its market share at around 75% of tablet sales, Apple remains at the top of the heap, so it’s no surprise that competitors looked to mimic its functionality with their alleged “iPad killers.”

But, said analyst Ross Rubin, executive director of NPD’s Connected Intelligence, “It’s not a question of slapping a lightweight operating system onto a piece of glass and thinking that will be enough to compete.”

Instead, competing is increasingly about staking out a niche.

For Panasonic, that means skirting the consumer market altogether, in favor of business-to-business solutions. To complement its line of Toughbook PCs, the company is launching 7-inch and 10-inch Toughpad tablets built for “mission-critical and highly mobile workers.”

The hardware runs on Google’s Android operating system, and boasts greater security features than a consumer product and a screen easily viewable in daylight.

Toughpad is “not just for great grandmothers who are playing ‘Words With Friends,’?” said Kip Walls, director of product management at Panasonic.

But this ruggedness comes at a price: The 10-inch Toughpad A1 will be available this spring for $1,299.

Other companies are encroaching on turf once exclusively dominated by LeapPad: baby and toddler users.

A number of new products, including the Fuhu Nabi Kids Tablet and the Vinci Tab, target tech-savvy toddlers at various price points, running on a modified version of Android with pre-installed kid-friendly software.

But analysts warn the niche route is not for everyone.

“That’s not going to be a big enough market for companies with big consumer brands and large distribution such as Samsung, Sony and HP,” Rubin said.

The latter, Hewlett Packard, provided the cautionary tablet tale of 2011.

In mid-August, just one month after launch, HP discontinued its TouchPad tablet, though it is still unclear whether that decision was the result of disappointing sales or whether the TouchPad was simply a casualty of HP’s decision to sell off its PC division.

Analysts have suggested an even bigger loser in 2011 was Research in Motion, the developers behind BlackBerry, whose PlayBook tablet and new operating system failed to meet even basic business needs.

“It was such a disaster, and to this day does not have a native email client,” complained one insider.

Rubin said 2012 will likely see an increased “blurring between tablets and notebooks.” Even though tablets are largely defined by their lack of a connected keyboard, NPD’s research shows users still like physical keyboards when doing work.

A spokesperson for hardware developer Asus said this accounts for increased sales of its Eee Pad Transformer, a tablet that docks into an included keyboard for less-mobile computing.

Avi Greengart, consumer devices research director for Current Analysis, said the tablets that succeed in 2012 will pair strong content with productivity features, like Microsoft’s Office suite, and new operating systems like Windows 8 and Android 4.0. Known as “Ice Cream Sandwich,” Google’s first OS to straddle both phones and tablets will further that pairing.

“Apple is almost a jack of all trades,” Greengart said. “You get a really nice combination of media and productivity in one device and no one has been able to match that so far, but Amazon seems to be having success.”

The online book retailer departed from its content-only strategy with the launch of Kindle Fire, a tablet that runs on a modified version of Android and is priced to move at $199. Though Amazon won’t release sales figures, analysts said the company has suggested it has sold more than 4 million units, proving there is room for growth in the market.

Other key players are simply updating their current line of consumer tablets. Samsung, for example, recently announced the hardware specifications for its Galaxy Tab 7.7. It will be the first tablet to feature a Super AMOLED Plus display — boasting a broader color range — which should interest content providers, but do little else to stand out from the crowd.

By the numbers

72.7 mil: Tablets shipped in 2011, accounting for 25.5% of the mobile PC biz in 2011

87%: Percentage of tablet owners who use the devices for Web browsing, followed by watch TV, movies, read books and play videogames

62%: Percentage of tablet users who play music on the devices

51%: Percentage of those who cite high prices as a reason for not purchasing a tablet

Source: NPD, In-Stat, DisplaySearch