Hmm, I believe you can monitor pledges and supporters at kicktraq.com. I agree though, having those tools available on each Kickstarter page would help encourage pledging.
However, a pledger already has the option to remove, reduce, or increase their pledge any time until the end of the pledge period. Even if the Kickstarter is at $5,000 out of $50,000 on the final day, there is no risk with giving a pledge. Unfortunately, the opposite is true - a pledger could pledge $10,000 on the first day and change it to $1.00 on the last.