So... i wasn't the only one that downloaded the software for testing some code. I don't have yet Arduano, but i'm interested about it. I found this very nice looking software Fritzing and i was very happy to construct some layout with different components and started to use Code tab for writing some code. I didn't understand that this doesn't do any simulation, this is only place to save code with sketch. I was so disappointed.
I think many would be ready to pay some amount for "Pro" version of software, that there is simulation. It would help so much to test some sensors and components before purchasing them.