I wrote earlier on the drama that ensued when a group of SF writers led a campaign to warp the nomination process by getting a small but sufficiently large group of supporters to collude on nominating a slate of candidates. The way the process works, with the nomination being a sampling process where a thousand nominators choose from thousands of works, it takes only a 100-200 people working together to completely take over the process, and in some cases, they did -- to much uproar.
In the aftermath, there was much debate about what to do about it. Changes to the rules are in the works, but due to a deliberate ratification process, they mostly can't take effect until the 2017 award.
One popular proposal, called E Pluribus Hugo appeals, at least initially, to the nerdy mathematician in many of us. Game theory tries to design voting systems that resist attack. This is such a proposal, which works to diminish the effect that slate collusion can have, so that a slate of 5 might get fewer than 5 (perhaps just 1 or 2) onto the ballot. It is complex but aimed to make it possible for people to largely nominate the same way as before. My fear is that it modestly increases the reward for "strategic" voting. With strategic voting, you are not colluding, but you deliberately leave choices you like off your ballot to improve the chances of other choices you like more.