Nothing really special. If cudaminer/ccminer had real failover support, ...
it will be console or windows forms app?

Did you see CGWatcher?
Windows Forms

Everyone likes a nice UI. I'm actually writing it for myself, but I think everyone else might like it too, so that's why I'll be releasing it.
Yep, I saw CGWatcher, it's one of my inspirations, next to CUDAManager, but I'm writing it from scratch.
I'm still wondering how I could implement the profit switching by multipool. OK, I could use the api from poolpicker to pick the most profitable pool over X days, but only for scrypt. I'm unsure if that's still worth it.
you can choose multipools who provide api statistic and collect information by yourself to site or db and then use that information for your switching tool