Is Olympus the business?

As a long time OM system owner and film user I am now starting to look for a digital SLR. I'm a bit confused by all the talk on the differences in sensors between the big two and Olympus. What I want to know is does Olympus match it with Nikon and Canon in image quality and sharpness? All the pics on screen seem a little soft to me. Are the actual prints sharper? Also, does anyone use their old OM lenses in an Olympus DSLR with the adaptor? Is it hard to focus and what is image quality like? What would be a good lens to get for the E620 for portrait and travel work?

Well just like anything else it is just a matter of what you want. As far as IQ the Olympus cameras have improved with each model. I made some great pictures with the 510 before I went to the E3 and the E3 is an improvement over the 510. Noise at higher ISO's has also improved. I haven't noticed any sharpness issues. My pictures always come out crisp.
As far as the adaptor goes I have used one and focusing can be tricky since the DSLR's do not have viewfinders designed for it. But it is doable.
I also think if you compare prices and features the Olympus line holds it's own. The in body image stabilization is a very nice feature which I would hate to give up.

I totally agree with Greg on everything. Manual focusing will be harder on the entry level Olympus cameras [however the E-620 has a slightly larger viewfinder than the E-510 before it] but not any significantly more difficult than on APS-C cameras which also have smaller viewfinders than the ones you may be used to.

Image Stabilization is an awesome feature to have on your body, it will end up saving you a lot of money in the long run if you intend to buy Image stabilized lenses, and it will stabilize your OM lenses as well. However, Pentax and Sony both offer IS in their bodies.

Another perk to Olympus is it has the shortest flange-back distance meaning it will take just about any legacy lens system with the proper adapter.

Olympus also has the finest lenses IMO, certainly the finest "affordable" lenses. The kit lenses are at the top of their class, and the expert line of lenses [12-60mm, 14-54mm, 50-200mm] are all fantastic for the money. In fact, the 12-60mm is one of the key reasons I shoot with Olympus.

As far as softness goes, I have noticed the newer cameras have been getting a tad softer than their predecessors thanks to stronger anti-aliasing filters, but the difference is only noticeable at the pixel peeping level and will certainly not be apparent in print.

The biggest downside to the E-620 IMO is the high level of noise at higher ISO when shooting in Jpeg. Because of this, you can consider the E-30 which is physically larger and heavier, and also more expensive, but offers much more professional control and a much larger viewfinder which will help focusing with OM glass.

Another thing to consider is the E-3 [which I just purchased] which is not much larger or much heavier than the E-30, however is a bit more expensive when *new.* It however offers full weather sealing and even more professional control, and the best noise performance of any of the Olympus cameras.
*buying the E-3 new will be about $1300, however getting an almost new demo body off of eBay will cost only $900, or even less. This camera is built like a TANK and so I was not afraid when I bought mine used.