There's actually a formal voting system among the core developers, when it comes to crucial decisions. Like the regular schedule of hard forks, it's designed to not get stuck like Bitcoin. Vetos are discouraged, discussion on IRC will often be enough to reach consensus, and minor changes are implemented without much debate (listen from 26:40).
The voting system that the Core Team uses is based on the CentOS voting system. Votes are not cast permanently, so a member can cast a vote at the beginning of the meeting and change it several times throughout. In order from disagreement to agreement, the following votes can be cast:
Veto vote (-1). This is generally discouraged, unless it is accompanied by substantive arguments rooted in project-relevant criteria (protecting the community, economic reasons, technical reasons)
Reservations vote (-1 or 0). Either a neutral vote, or a negative vote, coupled with reservations and concerns that are stated with the vote.
Stand aside vote (0). A neutral vote, which can be accompanied with some reservations, but which does not seek to block the vote.
Supporting vote (+1). Supports the proposal / idea / change. The voter would be expected to also indicate whether or not they will personally assist in driving the effort if successful.
In the absence of any vetoes, the votes are tallied, which gives both the result of the vote as well as an indication of the amount of support (or lack thereof). If the votes add up to a negative or positive amount then the outcome is clear. If the votes add up to 0 that is normally an indication of no support and only small reservations, in which case the matter is not blocked by the vote, but it is also not particularly supported. In this event the Core Team may choose to hold another vote, optionally at a subsequent meeting a week or two later, if the matter is such that it requires more positive support.
Our hope is that this process will prevent Monero from falling prey to "design by committee", but also prevent "design by Wikipedia" or "design by the person with the loudest mouth / most eloquent writing". This process is currently up for discussion and comment; please feel free to provide input on it.