I've read that people who heard the speech thought very low of it and quotes from the press referred to it as "The president's silly words." Of course, now the speech is considered one of the greatest in history. We're people just so upset by the slaughter of the battle that any words said about it would be met by this harsh panning?
The comments that were critical of the speech were from political opponents of the speech, Republican papers were as full of praise as Democratic papers were full of criticism. Just as a speech by Obama will be panned by conservative pundits and speeches by Bush were panned by liberal pundits, you have to keep in mind the bias of the critic when reading the contemporary comments.
As time has passed, the political positions Lincoln espoused in the Gettysburg Address have become generally universal in American politics, and the speech is praised for its eloquence in putting forward those positions.
Not all were upset. In a letter to Lincoln written the following day, main orator Everett (at two hours) praised the President for his eloquent and concise speech, saying, "I should be glad if I could flatter myself that I came as near to the central idea of the occasion, in two hours, as you did in two minutes." Lincoln replied that he was glad to know the speech was not a "total failure". (Source: Wikipedia)