The current debate about voter IDs centers around what kind of ID should be required. If you take students for an example, most students have a photo ID - their school ID. If it's issued from a state school (as mine was), it could conceivably be considered a state-issued ID. Currently, in order to register to vote, many states don't seem to require more than your social security number (there is an informational packet in PDF form, here
, on the NAACP's website). Some don't require more than a utility bill in your name at your current address - although to open my utility accounts, I had to give my social for each of them. So you come back to the SSN.
So the new voter ID laws being put into place are geared at restricting acceptable ID to photo ID consisting of a driver's license or a state ID card, both of which cost money and, more importantly, time. For lower-income voters, the investment of time to go during normal business hours to a local DMV to obtain one of those forms of ID is a burden, not to mention the actual expense of ID fees (the average for which seems to be about $30, based on my quick googling of "ID fees by state").
Additionally, it seems that many of the states that are instituting these voter ID laws don't always have the statistics or the data to support the voter fraud they are claiming to be worried about. The big one right now is Pennsylvania, and Commonwealth lawyers essentially admitted in court that they haven't done any investigations into voter fraud. I'm not entirely certain how exactly they are aware that it's so widespread - I'm thinking clairvoyance. *coughs*
Anyway, the ruling about the PA voter ID law is actually supposed to come out next week, and will probably set the tone for future voter ID laws. The question in front of the court is whether the bill is discriminatory and would impose an undue burden on any one group of voters. The question will not be concluded next week, however, since whichever way the judge rules, the case will be appealed to the PA state Supreme Court. So we'll get to see this unfold over the next several months, if not a year or two.