Bill Lavezzi has a great run-down of Issue 2 on his blog:
What would Issue Two do?
Issue Two would replace the present system of reapportionment with a system in which officeholders and party officials and would have much less control over the outcome.
Why is this important?
Our ability to elect good legislators depends on having competitive races. The present system creates both Democratic and Republic districts that are practically unassailable.
What's wrong with that?
It makes most Democratic and Republic incumbents virtually unbeatable and therefore takes away much of their incentive to represent their constituents.
How does it do that?
Typically, by carefully drawing district boundaries so that minority-party voters are "packed" into designated legislative districts and the majority party enjoys districts custom-designed to elect members of the party in power.
So this is about Republicans and Democrats?
To some degree. In statewide elections, Ohioans split close to 50-50 between the two main parties. But the legislative districts developed for the 2012 elections will almost certainly produce overwhelming Republican majorities in the Ohio General Assembly and the Ohio Congressional delegation: they were designed to.
However, it also means that many incumbent Democrats have districts drawn so that they can't lose. That decreases their incentives to serve their constituents.
Whoever wins the elections--state Senators and Representatives, and US Representatives--won't really need to meet with or listen to their constituents, because their districts have been designed to re-elect them.
In Columbus recently, I talked with an elected Democratic legislator who bemoaned what might happen to his "nice, comfortable" district is Issue Two passes. Since he's been a reliable friend over the years, I didn't tell him what I was thinking and should be obvious: he'd actually need to campaign in the new district.