Jeff Hauser's anonymous legal expert (well, I assume it's him or her anyway) has this to say in the comments:
The author of the legal analysis replies:
I don't think that it matters, for the legal analysis, that this is the end of Torricelli's term. Losing a senator for a few months, or even for a few votes, is a serious blow to a state's power to protect its interests. That fact is reflected in the founders' debates about Article I, Section 3, which provided for gubernatorial appointment of senate vacancies when the state legislature was out of session. William Randolph, for example, thought that the governor was not much to be trusted, but thought that losing a senator even for just the period in between legislative sessions was so serious that he was willing to take the risk.
So, I think you can't read the Constitution to say that states are barred from appointing senators even very close to the end of their terms. And, if it would be impractical to force the interim senator to stand for election immediately, I think it is unlikely a court would rule that you have to hold an impractical or pointless election. That was, actually, much the point of the Wofford case in the Third Circuit; that the exigencies of filling the seat took precedence over the state's primary requirements.
But, I think the posters have made a good point that whether or not the appointment would have the effect of extending a party's hold over a seat for a short period is a relevant question of policy. States will certainly consider that now, if they contemplate re-writing their senate appointment laws.
