"Touch a button, slide to unlock, and begin working *right* *now*"
Is not an Enterprise level of security. The discussion is about a tablet in the Enterprise. It is not a discussion about a tablet that you bring to work.
No Network / Sys Admin would allow merely a "slide to unlock" device access to Enterprise resources.
And seriously, I can't remember the last time I saw a Windows computer crash or "Explorer has stopped responding" and I support over 500 of them at work from Win XP to Win 8.
While there may be some developers who will continue to rely on the keyboard or the trackpad for input, there will be others who will see an opportunity in the touch capabilities of the tablet on the Metro UI.
There are thousands of legacy desktop applications that were designed for a traditional desktop. Microsoft is saying that you don't have to drop them.
I have been using a Windows 8 convertible tablet for a few months now and there are times when a real keyboard is more convenient than an onscreen one. Especially when you want more screen real estate visible.
There are also times when a digital pen is more convenient than your finger. Like when you are taking notes or drawing diagrams. (see MS OneNote).
My point is, can't these input methods coexist?
As the saying goes, "Use the right tool for the job."
Is it so hard to fold the cover back?
Pro 
