It's a nice gesture from the Governor, but in reality it is meaningless. If my sources are correct, the Big Ten only requires 8 of its 11 schools to pass anything including invitations of new teams. This is unlike the PAC 10 which requires a unanimous vote. Iowa could vote nay on giving offers to Missouri and Nebraska as a sign of solidarity with ISU not being invited, but I believe the vote would ultimately be 10-1 in favor of inviting the two other Big 12 schools.
The reason Governor Warner was successful in 2003 was that Virginia was the deciding vote on expansion. The 9 member ACC at the time required 7 votes to pass anything, and the presidents of Duke and UNC were vocally against expansion due to their worries about negative ramifications (less revenue per school, travel issues, etc.). Originally Miami, BC and Syracuse were the schools being considered. Warner convinced UVA that they could get VT into the conference instead of Syracuse by only voting for expansion if VT was included. The powerplay worked and now VT is a member of the ACC.
Iowa would only be able to have any ability to negotiate if they were the 8th vote for expansion. Unfortunately for ISU, I just don't see 3 other universities in the Big 10 being against expansion. Also, if there were 3 other universities against it, I could see the conference bending to the demands of another university with a more reasonable request or not even having an official vote on expansion at all. The Big Ten could keep from expanding if it really wanted to even though I would be surprised if that happened.
Also, the pitch for VT instead of Syracuse made a lot of sense from a monetary perspective. While taking ISU over Missouri, Nebraska, ND, Rutgers, Maryland or Pitt may make sense from an academic perspective (some more than others), it doesn't from an economics perspective. The Big Ten is going to want a school that minimally generates more money for the Big Ten as a whole than its individual share. If it doesn't, then expansion is not only pointless, but a bad business plan.