I find the feature in Anki that estimates how long it will take you to complete all of your scheduled reviews quite useful and motivating. Would it be possible for Skritter to monitor your average rate of completing queued items and then estimate the time required to hit 0?
It wouldn't matter if it ignored what was going to come up later. i.e. it could just look at 2000 reviews at 5 seconds per item or whatever and come up with 2000 * 5s = 10000s = 166 minutes