Well, everything we 'learnt' from testing turns out to be rubbish! Who'd have thunk it
Red Bull are not slow
McLaren are not fast
Mercedes are not reliable
No one who watched testing thought Red Bull were slow, they thought Barca didn't suit them great, and they are faster in Aussie than Barca. Different tracks, different situation. Due to several situations, they didn't really go for an ultimate one lap pace in testing, they did today. Mclaren were not remotely thought to be fast in testing, EVERYONE said they were slow, the only days they went "fast" they used either better tyres and lucky timing(Perez, super softs iirc), or people wanted to talk up Button because he did a "fast" time on mediums that wasn't remotely anything special.
Merc had two of the worst days, followed by plenty of good days, 2 lost days of testing doesn't mean good reliability, it means unknown. They went through the majority of two practice sessions without a hitch and lost 10 minutes. I'm 99% sure they stopped Rosberg as a precaution over what might have failed on Lewis's car, NOTHING might have failed on either car, it could have just been a mistake.
Lastly, Vettel did a qualy style run, low fuel, 2-3 laps, fastest lap on first fast lap. Hamilton did 10 laps, he did his fastest lap on lap 9 or 10 I believe, and he was only half a second down, that actually almost certainly adds up to Hamilton being faster on the medium tyre, 10 laps fuel is worth something along the line of 8/10ths of a second in pace, on top of 8 laps more wear on tyres that lose 1-2/10ths a lap. Hamiltons lap was actually pretty amazing, Massa's was close(I think he did 6-7 laps and faster lap towards the end) Vettel's wasn't impressive. Tyres more relevant to Hamilton than fuel as his fastest laps were end of the run, but he was still fast earlier in the run, he was fast throughout basically, so he showed pace with 10 laps of fuel on board, and still had pace with the fuel lower but the tyres worn as he'd done several full speed laps throughout the run. For a Merc compared to last year, doing a fast lap(faster than anyone but Vettel) on older tyres is a freaking massive sign of improvement for that car. The Merc was a complete dog on tyre wear last year, that he can be faster than all but a qualy run for Vettel after that long is a very very good sign.
On the super softs Vettel came the closest to doing an unimpeded run, but also after a couple bad laps of being held up, essentially super soft testing was a wash as no one with any speed had a clean first lap.
From testing and practice, Merc look very fast, Ferrari/Red Bull, toss up whose fastest but I suspect race pace will be with Ferrari even if qualy is with Vettel. Lotus don't look close to those three teams at all, and Mclaren look nowhere as they did all through testing.
Personally I think in quali it will be Hamilton/Vettel, with Rosberg and the Ferrari's and Webber fighting for 3-6. In race I think Ferrari/Merc will look very strong indeed, Lotus won't be very close and Red Bull will lose ground.