I can't agree with you more
As a small independent consultant, I couldn't agree with you more. My experiences match what you describe. I do software demonstrations, presentations and training with graphic design applications. My current toolkit consists of a 15" MacBook Pro bought two weeks before the surprise introduction of a 13" model. It's svelte compared to my workhorse 14" Dell laptop. I have an original iPad I take on the road too, primarily to hold digital manuals and documentation. There are times when I have to travel with all three. And all their assorted accessories as well.
I currently plan to retire the MBP, which I hope to replace by the start of next year with a 13.3" MacBook Air. Since it can now carry 8GB of RAM, a fast i5 chip and a 256GB SSD, it'll finally be powerful enough to meet my needs. I can also hook it up to a USB hub to external keyboard/mouse/hard drive and plug in a desktop display to run it in my office and my home as a plug-in workstation.
But if Win8 holds promise and docking tablets can provide enough horsepower for these hybrids -- even at a $1500 price point -- I'd change my plans and gladly dump both my WinTel PC laptop and my Apple-obsoleted 18-month old original iPad instead.
Replacing two systems for one is worth it alone -- especially when you're jetting between terminals to make airport connections. Less weight and less bulk wins every time. And after getting unceremoniously dumped by Apple with no future upgrades, blocked from using iOS6, the idea of systems with a solid, predictable upgrade path have a lot of appeal too.