My recollection of the last accident attributed to a microburst was July 2, 1994 (USAir 1016). Do you know of a more recent one??
We are definitely coming up to the mb season; June, July, August.
EAL 66 - June 24, 1975
Alegheny 121 - June 23 1976
PAA 756 - July 9, 1982
DAL 191 - August 2, 1985
USAir 1016 - July 2, 1994
That's just in the US, and those are only the biggies, there are more lesser known accidents/ incidents.
For a microburst refresher try:
http://www-frd.fsl.noaa.gov/mab/microburst/