With HP's decision to shutter its TouchPad just weeks after launch, the tablet market is looking more like the iPad market.

"Apple created the tablet castle and various competitors have tried to storm the walls, but nobody has made much of a dent," said Forrester analyst Charles Golvin.

HP's decision, despite a splashy debut campaign launched in July featuring comedian Russell Brand, teen actress and songstress Miranda Cosgrove, and "Glee" TV show star Lea Michele, was unexpected -- and expensive -- but follows its widely panned market entry. Reviewers mostly dismissed the TouchPad as too little too late, paling in comparison to the iPad.

One HP insider lamented just a few weeks ago, "How do you fix it? Marketing alone can't do it." He also acknowledged there were major culture clashes between Palm and HP employees all along the way in both product development and marketing for the TouchPad.

Indeed, marketing alone won't help any manufacturer scale Apple iPad's formidable fortress of market share. According to Ace Metrix, which tracks advertising effectiveness, of the 35 tablet TV ads that have run in 2011, eight were from HP, six from Samsung, five from Apple, and three from RIM.

Still, Apple reported shipping 28.7 million iPads from launch in April 2010 through May 2011. Forrester estimates that by 2015, more than 82 million people will be using tablets, with annual sales rising from 10 million (mostly iPad sales) in 2010 to 44 million in 2015.

That said, Samsung, LG and even RIM are not going to capitulate as easily as HP, he said. "HP was late to the tablet game as well as the smartphone market. ... Even if their tablet had been more successful, they still would have been shut out of the smartphone space and would have had to face that mountain."