Well, I made my decision. After spending hours working with both Apple's Aperture and Adobe's Lightroom I have made my choice. I will be using Adobe's Lightroom. In the end, I thought they were both good applications and reasonably priced (both at $299.00).
In the end there were just a couple things I preferred about Lightroom.
1. More resources created and published by users / photographers.
2. Better integration with other software I use (Adobe Creative Suite 3)
3. Available for both mac and pc.
4. Slightly more advanced output support within the print and web modules.
Overall, either application would have been a good choice.