I guess you all know some of these things already, but he's what I marked up:
McLaren:
- Hornets on the airbox
- Smaller barge boards that now are similar in size to those of Ferrari
- Connection between floor and flipup. Contrary to Renault, it seems like here the connection also is some kind of a vertical wing guiding air towards the centre of the car (helping the coke bottle shape)
- Thin and very nicely shaped chimneys
Renault:
- Slightly modified RWEP's that are a little longer at the top than at the bottom. At least for the lower part, as the plate ends right after the horizontal wing plate at the top.
- Connection/Support between the floor of the car and the flipup. Realised by a small vertical bar.
- Rather short chimneys pointing upwards. Outlet are foreseen with aelerons to allow better assimilation of air put out of the chimney and air passing by
- V front suspension
Williams:
- Smaller airbox air intake
- Really low sidepods that also quickly decrease in height towards the rear
- Huge chimney pointing outwards
- Biggest RWEP (smallest cutout) of all F1 teams at present
- small connection between body floor and flipup
Red Bull Racing:
- High exhausts putting out exhausts about in the middle of the rear wing's open area
Toyota:
- Rounder and smaller nose cone (somehow resembling a bullet)
- Pre-sidepod wings (similar big bigger to those Jordan used in 2004)
- Really huge FWEPs
- Front wing hangups pointing towards each other at the front
Ferrari:
- Extra element in the middle of the front wing
- 3-plate front wing instead of the previous 2 (and thus 4 plates in the middle)
- new RWEP still with a gurney flap at it's tail end