Just posted a similar thought in the General OmniWeb forum - and then found this post. Here is my post from General:
I too have been a long time user of OmniWeb and regret that it hasn't been getting much attention lately. I'm finding a few websites that don't work in OmniWeb or that work significantly better with other browsers. Unfortunately, that number continues to slowly grow.
Yet I dislike going to other browsers. OmniWeb has spoiled me with the tab drawer down the side of my screen. Spoiled me with being able to set site specific settings. Spoiled me with the way that bookmarks are organized. And spoiled me with a host of other features that I'm just not finding elsewhere.
With the open source extensions that Apple has provided in Safari, if OmniWeb is a product that will face less development time is there any chance that some of these great OmniWeb features could be developed as extensions for Safari? Just a thought to save development time yet please all us loyal OmniWeb fans out here.
The idea of using the standard WebKit to keep OmniWeb more current sounds like a good idea too. I'd prefer to continue using OmniWeb as OmniWeb, but like Andreas I'd be willing to pay for an extension to Safari that brought over certain OmniWeb functionalities to Safari. Perhaps a series of extensions? The OmniWeb Tabs extension. The OmniWeb Bookmarks extension. The OmniWeb Site Settings extension.