IBM Chief Technology Officer for the Middle East and Africa, Mark Dean, further fuelled the argument over whether we are living in a 'post-PC' era, when he claimed the company did the right thing in getting out of the desktop PC business.

August 12th marks the 30th anniversary of the IBM 5150 PC, which was widely considered to be the beginning of the PC era. IBM, for years, lead the way in ensuring a PC in every home, a campaign which in turn spurred an industry that now sells hundreds of millions of units each year.

Considering that Dean was on the team that helped shape IBM's PC business, his commentary is stunning. He lauds the company for selling its computer business to Lenovo in 2005. "While many in the tech industry questioned IBM's decision to exit the business at the time, it's now clear that our company was in the vanguard of the post-PC era," Dean wrote this week.

In the blog post, Dean admits his primary computing device is now a tablet. The PC is no longer at the leading edge of computing, and Dean argues that services, not another computing device, are leading the way.

However, not everyone agrees with Dean's picture. Microsoft Corporate Communications Chief Frank Shaw says he likes to think of the current state of computing as the "PC-plus" era. He adds that over 400 million PCs will be shipped in 2011 alone.

"We'll continue to lead the industry forward in bringing technology to the next billion (or 2 billion or 6 billion) people on our planet," Shaw writes. "We'll do that as we always have, by working with our partners to deliver amazing experiences to individuals and businesses."

That certainly sounds as if Microsoft thinks the PC as a platform will be around for a long, long time.