My picks go like this. In brackets, the first number is where I expect them to be when the European season starts, the second is how I expect them to perform between Spain and Spa, and the third is my expectations of their performance for the post-Spa part of the year:
1. Mercedes (1-1-1)
By a country mile. Will win most races and take both titles before the final race (the constructor's one ages before).
2. Williams (2-2-2)
Looks sorted, cool and comfortable in a way the other teams don't.
3. Red Bull (3-3-5)
As Williams, but something seems slightly off and I expect it to stay that way. Can't put my finger on it. May be vulnerable to Force India/McLaren charge later in the year but this will come too late to affect its championship position overall, especially since Ferrari (its main rival for the position) will fade sooner and faster.
4. Ferrari (5-4-7)
Will start the season well and then fade badly after mid-season, as Kimi loses interests and Sebastian wonders what in the world he's walked into. The car will not be quite as good as thought but this will not really be the main issue - instability and doubt will.
5. Lotus (4-8-6)
Will start very well, have a curious mid-season slump as Pastor gets more crash practise, before improving again at the end of the year. Romain won't win but will get plenty of podiums, making it obvious that the car is going to be a title-winner before the end of the decade, subject to funds.
6. Force India (8-5-4)
Start will be slow, improving to just behind Williams by season's end. Their car's reliability will see it getting points where McLaren doesn't, and there's a huge burst of funding due to reach development about now (meaning the second half of this year should feature some superb updates). Will be the only team to finish at least once in every position possible in a 2015 race.
7. McLaren (10-7-5)
Will start abysmally and improve to upper midfield, half a step behind Force India. Expect a surprise podium from Alonso in Singapore, and for Button to hold the fort as well as can be expected.
8. Toro Rosso (5-6-8)
Will start in upper midfield and gently slide down the order (but never to the point of fighting Sauber). Won't make the best of its opportunities because it has a raw line-up, but expect Sainz to do about as well as a Toro Rosso rookie can be expected to do. Verstappen will be in the wall a lot, especially in the first half, though never quite falling to the depths of a Maldonado.
9. Sauber (7-9-9)
Probably another year to forget, though at least this year there will be some promise. Nasr is going places and Ericcson will do a decent job of showing him the ropes and keeping morale up. They're in survival mode, but not to the same extent as Manor.
10. Manor (9-10-10)
It's doing well to be on the grid. It will be there at the end of this season and for the foreseeable future, but appearances in front of other teams will be reserved for besting limping McLarens in the early rounds and an occasional hard-on-its-luck-this-race team.