Whoa. That came out way faster than I thought it would. I just played around with it for a bit and like most improvements. I would love to be able to set individual timings for every picture in a slideshow, though. If that were the case, it would be a massively powerful tool to do multimedia slideshows a la MediaStorm. Most current solutions are either crap or ... crap. It can´t be hard, can it, Adobe?
About Aperture vs. Lightroom ... I´ve been on LR since the very first beta and it hasn´t put a foot wrong ever since. Whereas Aperture feels cumbersome and complicated to me. Plus, the RAW processing is only second to Capture1, which has a completely different target audience (think portrait/art/advertising/science crowd). In photojournalism, most professionals either use Photomechanic, Photoshop, Lightroom or a combination of two of them. PM has quite a few powerful tools for metadata and thus many agency shooters rely on that and PS for simple retouching/cropping. If you don´t need that super-special metadata stuff, LR is the way to go.