I certainly hope it doesn't have to be a 'write in' as that is always more difficult.
It is my understanding (based on an earlier thread) that her resignation was 'automatically' effective the day (7-15-02)she filed her candidacy papers.
In most states, voters have to jump through so many hoops to get a write-in to count that they usually screw up somewhere along the line and invalidate their choice. First, the voter has to register with the polling clerk that he intends to make a write-in vote, and has to fill out a form. Then he has to be sure to spell the name correctly. I don't know about Florida, but in some states the candidate is allowed to file a statement listing which written-in names should count for her (Catherine Harris, Katherine Haris, etc). If the voter's given misspelling isn't on the list, or the state doesn't allow such lists, or the name is written in cursive in such a way that it's not entirely legible ... any of those reasons could cause the vote to get thrown out.
Basically, if you think the RATS managed to come up with some original, unique ways of attemping to invalidate ballots in 2000, just wait until they get a chance to jump on X million write-ins. The stakes will be lower, but the war will be far nastier.
In short, Harris's name has to be printed on the ballot, or else she's going to need a miracle to win.