The real difference is in how fast you can achieve quality results. For standard photo processing, the differences are not going to be huge. You definitely have more creative control without having to export to Photoshop for some photo tricks, but in the end it's still another tool.

One of my favorite photo effects that I REALLY wished Aperture had was a Vignetting effect. Photoshops Raw processing had this from the start (I think), and I really didn't like having to export every photo to photoshop for a simple vignette effect.

Alas, Apple saved it for release 2.0 .. So here's a real world test of processing a photo with Aperture 2.0 ... It's a shot from Mimi & Teft's Shake Your Fantasy video shoot - Mimi and I sitting down. Here's the raw image exported:

And here's about 5 minutes of adjusting settings in Aperture 2.

As you can see, adjustments can be fast. And Vignetting is so moody!

Raw 1.1 and 2.0 differences

So far I can see that the Raw 2.0 converter preserves more shadow detail than Raw 1.1 ... here's my hair at 100% with Raw 1.1:

And here's Raw 2.0:

If you look closely at the root of my hair, you'll notice that Raw 2.0 has more detail extracted natively for the darker portions of the image. This is excellent for extracting the maximum amount of detail possible out of your raw files.

Now, the previous shots were taken with a Canon 40d, which already has a ton of color detail in it's 14-bit raw files. What about a 12-bit raw file from a Canon Rebel XT?

Here's a raw shot from Death Valley:

Here's a conversion from Raw 1.1 with adjustments a few months ago:

And here's a conversion from Raw 2.0 with NEW adjustments that I made today:

In general, I was able to achieve noticeably more shadow detail and contrast, while still keeping the integrity of the photograph intact. The new raw adjustment controls really allow you make refined tweaks without degrading the image, which is AWESOME! I also found that shadow noise was better controlled in the Raw 2.0 converter.

To sum up, is the upgrade to Aperture 2.0 worthy? In my opinion, yes. Aperture was already a cool tool, now it's even better!

Judging by there blog, they've got about 100k users and launched Picnik around January of 2007. Take note, Flickr and gang (Yahoo) may be plopping some doe on these guys to integrate this tool directly. It totally fits into there toolset (they probably designed it that way!) Take a look at Flickr's set/collection editor .... very similar. Except, Flickr uses Javascript/Prototype/Scriptaculous type tools instead of Flash based tools. But then again, having Javascript perform white balance and saturation and sharpening would be a huge task (imagine the cross browser compatibility nightmare that app would spawn!!)

I ripped there Picnik widget off of there blog code and posted it below, linked it to the Landscape Photography group. Click on one of the photo's and give Picnik a whirl!