I just read back through all the responses and wanted to clear a few things up-

• As has been mentioned previously- your employer only gets a tax break if they reimburse you for some of your cycle related expenses.
• You don't have to ride every day, you could probably ride in once a week and still claim the credit (that's $5 per trip or $2.50 each way)
• If you are unhappy the bill passed or want to whine about the other 'pork' that was added- there is a P&R forum for you to go whine about that. This is the commuting forum.
• The senator who was responsible for this is from Oregon where a huge number of people already cyclo-commute and may be helped by this. On the other hand, if you are the shopkeeper at the Burnt Corn General Store in Burnt Corn, Alabama, your employer may choose not to administer these benefits. I know this sucks, but if you weren't getting any incentive before, it's not like they took something away from you.

[/soapbox]