The monorail, as defined by the latest of five ballots, runs from Interbay to West Seattle, and does not stretch north of the ship canal. That doesn't mean it wouldn't eventually. The Seattle Monorail Project can't create a plan for something not on the ballot but it does not take much imagination to see a future monorail expanding north not just across the ship canal to Crown Hill, but then on to Northgate and why not link up with (a fictional) Lynwood, Everett, Edmonds Rail System (LEERS - You heard it here first).
In reality, the history of public transporation projects seems a reasonable precedent to the potential of a Seattle monorail. Transit systems in other communities tend to grow to accommodate the population and convenience needs of their community - and gobble up tax payer money, as part of their lives. The subway in New York City is far larger than the IRT that once occupied a patch of Manhattan. The London Underground, managing to be a model of both complexity and efficiency, is far more than its nineteethn century roots in Paddington. Closer to home, the Bay Area Rapid Transit in Northern California has new projects a plenty and even our our own Sound Transit is considering some 80 projects it will eventually winnow to a few for voters to consider next year as part of ST2.
A monorail would change the face of Ballard. It is already, temporarily, with construction cranes that will give way to new residential developments.
The arguments for and against the monorail have been volleyed around long enough that most voters don't need a rehash of the pros and cons, if they ever did. On some level, being for or against the monorail seems like a gut decision. It would be a shame if Ballard's future was defined by the guts of voters beyond our borders.