I still don't buy this argument. So by this logic, if today's technology allowed 1(or more) day battery life, enough memory, a big internal memory and all that jing-bang on a cell phone with a full blown OS to boot (all hypothetical mind you), would you say that you would like your desktop application to be ported over to your cell phone just so you could ditch your laptop/desktop and carry just the cell phone with you ?

No, I am certain you wouldn't do that , and that is because the desktop app is NOT usable in a cell phone form factor.

And how is it that different where a desktop application is ported, bells and whistles and all to a 4" screened tablet (except in making it slightly more usable than a cell phone) but still unusable really as a mobile application ?

The whole point of Netbooks is not to replace the large screen laptops either. It is useful for limited apps and browsing and connectivity and computing in a cinch. Would you think about using a netbook for high-power number crunching ? So what gives that a tablet should be a replacement for a laptop ?

I just don't see this vision succeeding in any way - for the simple fact that mobile devices are for mobility and also for ease of use while you are mobile. If its not easy, nobody will use it (except a few diehard geeks). (We are talking about Nokia mass-marketing the device mind you).