Personal Computers are "going the way of the vacuum tube, typewriter, vinyl records, CRT and incandescent lightbulbs" according to Mark Dean, Chief Technology Officer for IBM in the Middle East and Africa.
Writing in a blog post on the 30th anniversary of the first IBM PC (didn't know that, did you?), Dean relates how when he helped design the first PC, "I didn't think I'd live long enough to witness its decline", but says that PCs are "no longer at the leading edge of computing."
This decline is, Dean says, down to not any other specific device - smartphones, tablets etc. - but by the new roles computers are being asked to fill by users. Instead of coming down to the hardware, Dean writes that "innovation flourishes best not on devices but in the social spaces between them, where people and ideas meet and interact. It is there that computing can have the most powerful impact on economy, society and people’s lives."
IBM, which has long since withdrawn from the business of building personal computers, started out with the launch of the model 5150 (pictured) back on August 12th, 1981. The success of the 5150 and subsequent IBM PCs led to other companies' development of hardware that was designed specifically to work with IBM computer systems, and IBM's dominance over the market. You can read what else Mark Dean has to say on the PC's history and future at the link below.
Link: A Smarter Planet