Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)
Only when mac os and ios merge. It will be one big cloud-oriented os with possibility of some sort of bootcamp. Although imho i think win will also have some sort of cloud-oriented os. So, you will have possibility of runnig all apps you want - all you need is log in on winCloud or macCloud.
This will be the day when freedom in the internet dies. You will be able to run only "approved" apps (it will a LOT wors then today's appStore), all your posts, searches etc will be tracked, as well as your gps coordinates 24/7. This will be perfect opportunity for OPA. 60-90% of world websites will be closed. Macrumors want be exception (rumors, forums, blogs, opinion in general will be considered as evil).
There will be one internation organisation for controlling and registering websites. Opening site will be more expensive and more complicated than opening small business.
Your devices will replace your payment methods, and eventually your id.
By that time all physical information-carrying devices will be illegal (hdd, sdd, clean cd etc). You will have instead your personal/education/work cloud server that will be an object of harsh censorship and penal code.
As the result, the art in general will die. Musicians want be able to promote their music. There will be one online music store, you want be able to record your music on cds and make demos, all public concerts will require licence (harder then medical licence). Same thing with cinema. Same thing with books. I doubt they will censor beatles-elvis, or old movies. But no new such talents will appear.
That is when ipad will replace home computer

i would give 10 years, 15 top