My few cents on this topic.
Desktop and Laptop Market is for -
1) Education, research and development
2) Audio, Video and other media development
3) Commercial and non-commercial software development
5) Offline data management
6) Faster computing
7) Office and other routine tasks
8. online shopping
9) Books and other publishing media
10) Gaming - web dependent and non-web dependent
and many more...
You can see that desktop and laptop market perform - creation, consume and sharing of the data. It's not stuck on any one particular task. This platform makes use of powerful processor be it core or graphics. Laptops are yet to catch up with the processing speed of bigger machines and in some cases not even desktop cores but still they're offering almost everything that desktop can offer.
Tablet market is for -
1) Browsing the internet, emails, watching videos
2) Online shopping
3) Book (read)
4) Phone ?
5) Art (draw/photography)
As you can see tablet market is for those who consume and limited data creation possibility. So basically tablet users have more limitations on data manipulation. Sure they can use external keyboard and mouse to some extent. But tablet processors are not yet matured enough to disturb any of the desktop or laptop platform. You can watch youtube video or do skype on tablet but you can't do encoding of the video on your tablet. Arm processors are not fast enough to manage that. Similarly you can't use tablets for development activity with these processors as of now. One more point is about broken code and fixing thee same on tablets. You can't fix many issues of your browser or OS on your tablet if you have no external keyboard and mouse or access to another machine. Tablets are also limited with storage for now. AFAIK, there is no tablet with 1TB storage, you have to depend on external drive.
One important point most of the tablet users are forgetting before making comments like -"deskptop is dead already and you're living in cave with dekstops", that screen size is very important. Today we have screens which have ports to get input from deskop. But considering the amount of processing it needs for data manipulation tablets are not ready for handling big screens (they're not mac mini yet). I don't know if tablets can give you feel for HD and 3D movies like big screens.
As for cloud apps - If you want someone else to take care of your family pictures, videos and purchased mp3s then you have nothing to do on desktop/laptop. You should migrate to tablets to save money. But if you've privacy and data loss/tampering concerns then cloud has nothing to offer you.
Yeah, 2++ cents.