That's correct, there would be a GUI, and anyway some components on a centralized server. Votes can also be integrated on a centralized server, I was just wondering if it was already available in bitshares.
So yes, it sounds indeed feasible to register the votes of token holders directly on my side, but that would be ugly and centralized 
Thanks to you Ravid and xeroc for your support.
Well, you said that people will vote on stuff related to your company. I am pretty sure the stuff to be voted on will not be shown in the Bitshares wallet as it has nothing to do with its network. So you'll need a centralized voting hub anyway and it will do the weighting and calculations.
On the other hand, if you are an established company with a budget, you could hire a developer that could implement the voting with your company token on Bitshares. Some kind of flag would have to be added to the workers/improvement proposals/your stuff so that Bitshares-related proposals wouldn't show at your hub and yours on ours.
Bitshares devs are pretty busy as they are, so you'll need to hire your own and get him working with our guys