I have my new Olympus E-30 for about two weeks and I must say, I'm in love with the camera. I upgraded from my older E-510 and must say, that the E-30 does all the things I did not like from the E-510 better. Which does not mean that the E-510 is not a good camera and will it certainly will see more use in the future, but the E-30 is just what you expect when upgrading from entry level DSLR to semi-pro DSLR.
So, what's new?
The first (and I think most impressive) thing is the new sensor. While noise is not much better compared to the E-510 (especially, since you should use ISO 200 as default with the E-30), the improved dynamic range is.
The E-510 had a tendency to clip highlights at outdoor shots, which I personally found to be very annoying. Yes, with correct metering and exposure you could prevent that, but it distracted from what you really wanted to do: Taking pictures.
The E-30 is just soo much better. You can shoot away without fear that you did not follow some esoteric formula to save the highlights. You see something worth capturing, you compose the image, you shoot. That's the way it should be and the E-30 really makes it a pleasure.
This process is added by the enhanced liveview mode compared to the E-510. The new hybrid focus mode that works with every lens without flapping the mirror makes liveview really usable, especially in combination the the turnable LCD screen. It makes composing shots from special angles so much easier and I found that the portraits I did with the E-30 are just so much more creative than the ones I did with the E-510.
Last, but not least, the Jpegs ooc are great. I switched from using RAW (which I always used with the E-510) to Jpeg. From time to time I make minor adjustments of sharpness, contrast or white balance, but most of the time the image is just good as it is.
The new Viewfinder is bigger than the one in the E-510. However, I never thought about that viewfinder as being too small, so while the increase in size is nice, it does not carry much weight for me. Due to the increased amount of AF-Points, more of the viewfinder is covered with markings, which actually distract from the image behind.
Speaking about the AF, I don't think that it's particularly faster or more sure than the one in the E-510. Here I expected more. The additional AF-Points, on the other hand, are nice to have. They give you greater freedom in composing your shots, especially for portraits where you turn the camera (don't know the proper english term, sorry) for 90 degree. With the E-510, you could ony choose to fokus on the upper and lower parts in this picture. Now, with the E-30, it allows you to fokus on the sides of the picture too, making it easier to follow the golden rule of composing.
All in all, I'm pretty fond of the camera. It's a bit bigger than the E-510 but in a pleasant way. The E-510 suited my hands the best of all entry level cameras, but the E-30 seems to have been made for my hands.
The only reason not to get this camera would be if you mainly focused on high ISO photography - in that case, the D90 might be a better purchase.
A portrait taken with the 14-54mm I at ISO 3200 ( mistake on my part). It's postprocessed, but you can still see the noise in the darker part of the image
Taken with the 14-54mm and the EX-25. No postprocessing:
Taken with the 14-54mm I: Lot's of dark and light areas in this photo, no problem for the E-30. This one uses one of the E-30 Art Filters.