plants are overstretched.... how far away is your light? It should be within a few inches if its florescent and within 8-12 inches if its hps or mh, but other than that looks like you are doing fine
Yeah i agree, plants are stretching way to high. You either have not enough light or its too far away. Are you using floro, CFL, MH, or HPS? I'd bury your stretched seedlings down further and let that part of the stem root out. But other than that they look very promising.
I would just make sure that you have atleast 5000 lumens with floro. Thats what i had when i first started my veg on 3 plants but i moved to HPS. For flowering im using HPS and LED.