Holy hell, I should've done this years ago. I just kept putting up with a silly workflow of storing things in iPhoto and exporting them individually to Photoshop. Considering Aperture is only 80 bucks, I really wonder why I waited so long. It's a great upgrade, with a proper adjustment set, more flexible layout, but still fits nicely for those used to iPhoto.
Pick it up. $80 in the Mac app store. Well worth it if you are already managing your stuff with iPhoto.