"First day to circulate and file nomination petitions February 15"
"Last day to circulate and file nomination petitions March 8"
"First day to circulate and file nomination papers March 9"
"Last day for withdrawal by candidates who filed nomination petitions March 23"That last date March 23, 2011 was not just the last date for the withdraw of a candidate it's also the last day to have someone not appear on a ballot because he or she is not qualified in some manner to hold office.
But there is usually an air of secrecy about running for office. So, it will probably be a few days after March 9, 2011 or so when the petitions are officially in before you know who actually is running.
If by some chance no one invests into checking for a criminal record and March 24, 2011 comes around and the process of making up the ballots begins; felony conviction or not that person will be on the ballot.
If by some chance a person with a felony conviction wins an election and takes office it might take months of legal work to have them removed.