The total vote for President in New Hampshire in 2004 was 677,738, with Kerry getting 340,511, Bush getting 331,237 and the rest scattered. Total turnout for the 2008 primary as a percentage of the 2004 Presidential race was 78% with the Democrats coming in at 84% and the Republicans at 72%. "Unprecedented" is the proper word to describe the turnout. So much for 2008 being a low intensity political year.
The Democrat turnout is particularly remarkable considering that the 2004 primary turnout was 65% of the 2004 Presidential election Democrat turnout and the 2000 primary turnout was 58% of the 2000 Presidential election Democrat turnout. The Kerry-Dean New Hampshire contest in 2004 was a pretty tough fight with both candidates being well known due to their home states proximity to New Hampshire yet it appears that 2008 may leave it in the dust.
On the Republican side the eye catching numbers regard John McCain. He hasn't exactly strengthened as a candidate with the passage of time. Romney was certainly more popular in New Hampshire in 2008 than was Bush in 2000 but that does not account for all of the 23% drop in support for McCain. South Carolina may be the end of the road for McCain for the second time.