NASA GISS has revised their surface temperature data and 1998 has been determined to be only tied for the fourth warmest year. For January-December their top years (relative to the 1951-1980 average) are now:
2007, 2009 +0.57°C
1998, 2002 +0.56°C
The NASA page doesn't give the uncertainty in these numbers -- they should -- so it's hard to see any real difference in positions 2-7.
Regardless -- it's been very, very warm lately.
Here's a paper that explains their recent revisions.