After sifting through various threads, the following conclusions seem pretty clear to me:
Torricelli's name cannot be removed from or replaced on the ballot. It is past the 51-day deadline, and some military ballots have already been printed and sent out. Any attempt to circumvent this hard deadline will absolutely be swatted down in court.
It is irrelevant whether or not Torricelli resigns. There are all kinds of legal reasons that require the Senatorial election to proceed in November, and the winner of that election to become Senator for the next six years. All the hysteria about postponed elections or special elections is bullsh!t; it can't happen. If Torricelli resigns, the governor would merely appoint another Democrat to fill out the remainder of the current term till January -- that is it.
A write-in campaign is possible. With a high-profile candidate (like Bill Clinton?) and the incredible amount of publicity thereby generated, there is a slight chance of it succeeding. But not much of a chance, since the Torch's name would remain on the ballot, and too many Democrats would still vote for him. Write-in campaigns are incredibly difficult and expensive.
The Torch could promise to resign if re-elected, so a designated replacement Democrat could be appointed. He'd have to convince people that he could be trusted to keep his word about resigning. This is probably the Democrat's best hope, but it is pretty weak.
The Torch could try to regain momentum. After the courts rule that his name must remain on the ballot, he'll tell the voters that he tried to do the right thing and sacrifice himself for the good of the nation, but the evil Republicans prevented it. So he has no choice but to fight on, and the voters should refocus on the larger issue (Democrat control of the Senate) and come home to re-elect him. This is the most likely scenario, since none of the others work very well, but I doubt it will turn around his poll numbers.
Bottom line: The Torch is toast, and the Republicans pick up a Senate seat.
Forrester needs to campaign TWICE AS HARD now, and get out a POSITIVE message to innoculate against any shenanigans like a write-in or gaming the ballot... If the Dems see they cant knock him off, they'll give up the ghost on this.