.....So I ask you why is there not a possibility of using a thin, I mean thin like a ball-pen, stylus to write on the iPad screen ? Is the touch panel not that sensitive ? ....
I am not the developer of this fine looking note taker app, but....
A thin writing stylus for the iPad isn't likely to happen for either current generation. If it were possible, by now, either one of the many available capacitive touch styli (boxwave, targus, alupen, etc.) would have had a pointy one or an app developer would have worked some magic. All these people writing apps with zoom features or making a stylus with a fat tip are not doing so because they think that is the best user interface possible....they would make thin tip if they could.
My only guess is the iPad's screen, though precise, is tuned/meant to be used with the human finger...something that isn't pointy. Having the screen work with pointy objects likely requires a less optimized for fingers or additional tech, and with Steve Jobs saying if you need a stylus you are doing it wrong (to competitors) then it seems doubtful there will be a change, but you never know. If a change comes, it will be in a future iPad.
Tablet PCs of the last decade have had active and passive digitizers (vs the iPad's capacitive screen). These digitizers allowed for a thin tipped stylus, but also required horsepower to interpret those sensitive touches. And because they were tuned to interpret the tip of the plastic (or special) stylus, they were not tuned to be used with your finger.
I think they tech will be there for layered digitizers to get both worlds, but it isn't there with any manufacturer that I know of.
If you just want digital note take look to something else, or even a livescribe and have it both on paper and digital. Or "make do" with the iPad and zooming in.