Laptop/Ultrabook comparison with Tablets seems like an apple-orange comparison to me. They make sense in their own unique way and one may not be a replacement for the other.
I am curious if iPad has cannibalized Apple's laptop business.
I agree. The Tablet market is mostly for people who used laptops for more frivalous uses. After the demand for information portals is filled, you will still have a large base of installed PC systems providing the bulk of the worlds basic business tasks. In the end, your computer needs to do useful things. I need a word and excell variant to do my work. I have yet to see a tablet that fills that need with a keyboard big enough for my fat fingers. So I will be sticking to laptops and desktop PC's for the seeable future.
The installed base of PC's is projected to be 2.3 billion in 2015. Given a sales rate of 360 million units per year, that implies a 6.4 year product life. This seems like a reasonable number, I have seen PCs stick around for a decade before being scrapped as too old.
I see the sales trend as indicating the PC market is maturing. The hardware is not improving so fast that you need to replace it to stay on the cutting edge. Instead people are tending to keep them till they break, and sales are more reflecting replacement than market growth.
Part of this phenomena is the fact that most users'
PCs are simply powerful enough. Even for professional work, they're probably ok. You might need a new PC for mechanical CAD, maybe for EE CAD if you're doing way too much FPGA floor planning or PCB autorouting. Video work's a big one... PCs are never fast enough, but that's still a niche. I needed a memory upgrade a year ago for some hardcore photo work (image compositing), but my three-year-old 6-core CPU was still fine.
Meanwhile, the tablets are fun, cheap, and sometimes actually useful. I stopped carrying a laptop to most things, replacing it with an Android tablet (does have a keyboard option). No, I can't edit schematics or draw PCBs on this tablet.. but that didn't work well on the laptop, either. My last few jobs have been Linux-centric, so there's no need for MS-Office; if you don't absolutely need that, there are plenty of office tools just dandy on a tablet... that's not remotely a heavy lifting job these days. I wouldn't use the tablet as a desktop replacement, but it's superior as a note-taking device in an all-day meeting (had one last week that went 11.5 hours, the Transformer had enough juice left for the 3 hour ride back home).
First iPhones and now iPads supplement laptop computers for mobile applications. Are there any statistics on how many people use an iPad alone without a computer? Are all of them "light" computing users who only want email, web browers, social media, electronic document readers, and games?
Laptops/notebooks and tablets have different use cases.
Tablets are media consumption devices. They are essentially half-duplex, with a UI optimized for choosing what media you want to consume. They're handy if you want to browse the web, read an eBook, watch a video, look at photos, participate in social media, or read and reply to email. They are popular with consumers because they are comparatively cheap, light, easily portable, and web surfing, social media, picture and video viewing, and reading and replying to email are mostly what consumers *do* with computers.
If you do content *creation*, a tablet likely isn't what you use. You almost certainly want a full keyboard, and likely a much bigger screen than a tablet will possess. You don't write a book, create a large spreadsheet, do image manipulation in Photoshop, or edit audio and video on a tablet, nor do you write, edit, compile and debug applications.
While the PC market is stagnant and beginning to shrink, it's hardly going away. All the things you can't do on a tablet still need to be done, and devices are needed to do them. When people claim the PC is dead and tablets are taking over, I ask where to get some of what they're smoking.