That's a nice start
Get ready for some critiques:
The top buttons are really good, they have a nice, crisp pop to them. As are the orange boxes. Very slick looking.
The logo could use some work... It looks too squished for no good reason. A circular logo might fit better. Also the logo is a little fuzzy... it doesn't have that same pop that the buttons do. Lastly, the green on the gear is mismatched with the green in the header, which looks odd. And the yellow is clashing with the orange in the boxes below.
Having the title in white text and the subtitle in black text is a little awkward looking, I'd do them both in white.
The screens on the right look good, but they need to be lined up in relation to each other. The front screen looks like it's resting on a lower plane than the three behind it. But the concept is nice, and they look pretty sharp.
The halftone on the gradient border doesn't seem to mesh well, and I think it has to do with the severity of the green gradient. The gradient is too dark at the top and too light at the bottom, if you evened it out a bit more I think it would flow better.
The rounded corners at the bottom of the header look good, but i think it's overkill to repeat the same motif in the columns below. Squaring off the columns, or giving them the same sort of rounded corners as the bottoms of the orange boxes, might fit better. As it is now, it looks like the orange box doesn't quite fit snugly into the bottom of the gray column area.
Good start on the mockup so far though, overall I think you have the beginnings of a decent looking design, with some tweaking it could be really ace.