qb.jobinfo() also returns a list of jobs. Try:
import qb
infos = qb.jobinfo(id=2500)
if len(infos):
for job in infos:
print 'job id %(id)s - %(name)s: status = %(status)s' % job
print 'jobs are dictionaires, so you can get the status as %s' % job['status']
which prints out:
job id 2500 - maya render dirmap_test.ma: status = complete
jobs are dictionaires, so you can get the status as complete