Apply for PhD before finishing my Master's degree I am now in the middle of my master's degree and I plan to graduate in August 2015. I currently study in Germany and for most engineering students here it is common to finish the five-year program (3 or 3.5 years for the bachelor's degree and 1.5 to 2 years for the master's). I'm thinking about applying for robotics PhD programs at different US universities but I noticed that most of them have a deadline in December for programs starting 9 months later. I don't have any publications in any international journals because in Germany this is mostly done by PhD students. But I have worked a lot during my studies (1 year internship, part-time research in university).

I don't want to lose one year waiting to start my PhD but in the same time I think that my master thesis will be a great asset while applying for such a program, especially when I will be willing to continue my research and PhD thesis in the same field as my master thesis. Do you think I should take the GRE and apply for next December or wait until getting my master's degree? And how this would influence the selection process.
It's not a big deal for you not to have publications—remember, many of your peers also will not have published anything, either!

Moreover, it's important to note that in the US, most of the applicants for graduate school do so in the fall of their fourth year of studies—which would, contentwise, typically line up with the third year (or sometimes even second year!) of study in a German program. So, in many ways, you're already much more experienced than your counterparts.

If you're interested in doing this, I would recommend that you just go ahead and apply. The worst that can possibly happen is that you're not accepted, in which case you find another means of achieving your goals.