"Facebook won't disappear in five years, but I'm confident they won't see the same growth rates as they are seeing today," he added. "Even with the rise of more vertically-oriented sites like Pinterest, Instagram and Goba, consumers will need a social home-base where all their acquaintances and friends are accessible."
However, there's always a new company nipping at the heels of every market leader and it will be no different for Facebook.
"If Facebook fades, it will be at the rise of other, more nimble companies," said Moorhead. "This is no different than the fading of AltaVista, AOL and Yahoo. Consumer taste and technologies change, and if you are the 800-pound gorilla and miss a beat, you may be headed down."
Dan Olds, an analyst with The Gabriel Consulting Group, said Jackson is right that mobile will play an increasingly important role for any Internet company, especially social networks. However, he said it's premature to count Facebook out of the mobile game.
"Facebook is making slow progress on the mobile front," he said. "Most users find the interface to be hard to see and use. But Facebook has recently redesigned its mobile interface to make it easier to see pictures, for example, which is a step in the right direction. But they also need to build a mobile-enhanced business model in order to attract advertisers, as well."
Brad Shimmin, an analyst with CurrentAnalysis, agrees that mobile will be important - either as a platform that helps Facebook prosper or as a platform that causes it to stumble.
"It is simply a hugely important market driver, which will most likely play a significant role in Facebook's future, depending upon whether or not the company is able to respond to this sweeping trend," he added. "I think we're still a ways out from seeing whether or not their recent mobility endeavors are going to play out in a positive way. But as with their security issues in the past, it is in Facebook's overall favor that they're attempting to tackle this difficult area."
Olds noted that Facebook is no longer the young start-up it once was and its executives are billionaires and millionaires. That means there will always be someone quick to point a finger at its challenges and call for its demise.
"Whenever a big successful company stumbles or even fails to move quickly enough in the right direction, there's always a chorus of folks ready to kick them at least a few times," said Olds. "There's a lot of that with Facebook these days and we can expect to hear more of this over time."