You are correct that a referendum on recent Ohio election law changes would stay the effect of HB 194 and other election changes until after the 2012 election. Ohio Const. Art. II Sect. 1 c sets the referendum for “ the next succeeding regular or general election in any year occurring subsequent to one hundred twenty-five days after the filing of such petition, and no such law, section or item shall go into effect until and unless approved by a majority of those voting upon the same.”
Thus the law would be suspended until approved by the voters. Article XVII sets elections in November. Because the Ohio Constitution allows 90 days for petition signature gathering and the election may not be before 125 days after the petitions are filed, the bills would have to have been filed by the Governor in early April. The Governor signed HB 194 on July 1.
Here is a comprehensive chart from the SoS’s office: http://www.sos.state.oh.us/SOS/elections/issues/StateReferendum.aspx
Here is also the election calendar for the year: http://www.sos.state.oh.us/sos/upload/publications/election/2011ElectionCalendar_85x11.pdf