The code below which I found on MSN did not worked to automatically word-wrap a cell:
dataGridView.Columns[0].AutoSizeMode = DataGridViewAutoSizeColumnMode.D
This may help someone.
If you need target specific columns use the below as what is int he question will not work, as items is not available in c# 4.5
dataGridView1.DefaultCellStyle.WrapMode = DataGridViewTriState.True;
dataGridView1.Columns[2].AutoSizeMode = DataGridViewAutoSizeColumnMode.DisplayedCells;
dataGridView1.Columns[2].DefaultCellStyle.WrapMode = DataGridViewTriState.True;