I was reading through this interesting article on UI innovation when I came across this line
In current interfaces, tasks are needlessly compartmentalized. Say you are putting together a presentation and want to place it on your website. You need PhotoShop to edit any images you use, Excel to do a financial spreadsheet, PowerPoint to compile the presentation, Dreamweaver to create the appropriate web pages, Mozilla to check it, and an FTP client to upload it when you are done. A substantial portion of your time is flat-out wasted when you are moving content from one application to another: You are fiddling with the tool and not being productive. To make matters worse, there is the time loss and frustration from errors caused by the significant mental overhead required to switch applications, each of which has its own idiosyncrasies — A keyboard shortcut may make text bold in PowerPoint but create a bookmark in the Mozilla; You may be able to spellcheck in Dreamweaver, but not in Photoshop. A user should not have to worry or think about what application they are in, and any habits they form using the system should not be betrayed.
If you use a web-based email account, how many times have you wanted to spellcheck your email only to be forced to either use an awkward web-interface, or transfer the text to a different application, spellcheck it there, and transfer it back? Why can't you just use a full-functioned spellcheck command right there? The same spell check (and same code) that you use everywhere else. If you want to edit an image on your website, why should you have to download it with one program, edit it with another, and upload it again? Why can't you just edit the image in the browser? There is no good reason but for the inherent limitations of the concept of applications. A user should be able to issue a command (like spellcheck or change contrast) anywhere, at anytime, and have it always do the same thing. This is truly humane. It cannot be achieved with our current application-centric computing model. Thus, in THE there is exactly one workspace in which you keep and view your content and instead of standalone applications we have command sets.
Hmm...doesn't this sound exactly like what ActiveX controls and OLE did years ago? Drag drop a spreadsheet into Word and have Excel's power instantly.