I'm playing around with Construct2 since roughly a week and having much fun trying out different ideas I had in my mind for ages - it is really an awesome tool =). One thing that I really would like to see in future versions is the possibility to switch to a dark skin. It is easier on the eyes when you work for several hours, and therefore I use a dark skin in every software that provides that option. Have a look at the new photoshop, at modo or unity pro to get an idea what I'm talking about. I can understand that a dark skin won't fit as the default, as it looks more "intimidating" and less friendly for new and potentially new users, so I wouldn't change that. If it is a serious task to implement that feature, you could also consider making it only for the paid versions of construct. I think it might even be another reason for some people to upgrade. Unfortunately I already have, so there is one less customer you could have convinced to buy for that reason - just kidding ;)
Thanks again for that awesome tool and feel free to tell me your opinion on my suggestion. See you around!