is wpf (technology) based interface is good for Point of Sale application?
my fears are wpf is immature, slow, eat memory too much, processor clocks in short required good machines which i think POS terminal doesn't has...
plus point i believe are
cool and powerful interface, good for win 7 and touch screen based but i dont' know how good machines/terminals normally people get for POS
any suggestion.. either winforms or wpf for POS app?
I agree with Martinho Fernandes that WPF shouldn't be considered immature. That said, as with all things, it depends...
The first step in creating any architecture is understanding your requirements and constraints. In this case it sounds like you need to learn more about the hardware and run-time enviroments.
Most importantly: Will machines have .NET 3.5 installed?
In my experience, WPF doesn't use more hardware resources than Windows Forms for the same tasks. Sure, WPF can do all sorts of hardware-intensive things with the graphics card that would be (close to) impossiblw with Windows Forms, but you don't have to use these capabilities just because they are there.
I would be suprised if we see more development of Windows Forms from Microsoft. WPF and Silverlight is the future for rich clients, so unless you have very compelling reasons to choose Windows Forms, WPF/Silverlight is the way to go.