Nancy Pelosi (and all Congressmen and women) are up for election every two years. Congressional elections are held in November of even years.
Mrs. Pelosi has gained more than 70% in all of her re-elections since 1992. The best any Republican challenger has done is 18% (Elsa Cheung in 1994).
Nancy Pelosi's salary is $174,000 per year, which is the salary for all members of the House of Representatives. The Speaker of the House makes more: $223,500; currently, Leader Pelosi is not the speaker, but rather, the minority leader (since the Democrats are currently in the minority in the House). Also, as a member of the United States House of Representatives, she receives a very generous health plan.
As of October 21,2010, polls seem to indicate that Pelosi will be re-elected to a Republican controlled Congress and so will not be speaker. Of course polls are often inaccurate and people can change their minds before they actually vote.