Ferrari were quickest in testing, but they were quickest last year too. McLaren getting so little running is a bit of a concern. Vettel ran more laps than McLaren.
Although GP2 (yes, I know they rebranded, but I refuse to call a spec series "formula") is the series to watch as far as I'm concerned. Looks like at least seven different drivers all have a decent shot for the championship and they can still overtake in that series.