Should I wait or get the A57 now?

[aperturekinetics]

I got a Canon 600D with the kit lens and a canon 50mm 1.8 last year when it was newly released. I think the price fell around 200 dollars i think after a year.

1. Should I wait for a price decrease for the A57 too?
2. Are the DT SAM 50mm 1.8 & 35mm 1.8 good as the Canon 50 1.8?
3. Is there any zooms focuses silently but still have a fast aperture? I like to do street photography...