I hope Safari remains a simple light-weight browser. I already think Apple went overboard by adding the tabbed-browsing concept.
That's because you hate tabs. Not because it's a "heavyweight" feature.
Safari for the people that want a simple browser.
OmniWeb for the people that want a heavy-duty browser.
If tabs are an "advanced" feature that bring the browser from light-weight to heavy-duty, why is the tabless OmniWeb a "heavy-duty" browser and Safari is a "simple" browser?
If Safari keeps piling features that only a select few would like to use, we'll end up with another heavy-duty browser and no more simple browsers will exist (until someone else decides to fill that gap using Webcore to ease the development.)
Most browsers can be as simple as you want them to be. Compare Safari to, say, Mozilla/Netscape or IE. Mozilla and Netscape especially are huge, incorporating tons of features like a built in email client, instant messaging, a news reader, an HTML editor... you get the picture. I think that is what the definition of a "heavyweight" browser is - one that is less of a browser than a suite of integrated internet applications. Like AppleWorks for the internet. I personally don't like it. I see Safari (and OW, and Camino) as a lightweight browser. Some have features that others don't have. Tabs and autofill/keychain are just two nice features that Safari just got. That nice pop-out text box is a cool new OW feature. And Camino has always been sort of the pioneer of tabs on the Mac platform, even if Mozilla was out first.
Assuming OmniWeb will eventually be on par with Safari in terms of rendering speed (when they start using the same Webcore), why have two similar browsers?
Because your browser is sometimes a very subjective and personal choice. No browser is "better" than another... well, usually not. I'd say most modern ones (yes, even IE 5) are approximately similar and the only reason one person chooses one over another is because of little features. I'd pick Safari over OmniWeb because of the tabs. Maybe once OW5 comes out, if it's really nice, I'll try that out and prefer it over Safari. Having choices is good. So when you ask, "why have two similar browsers?" I say, "why not?"
If you want customizable toolbars and other neat-o features, you might as well use OmniWeb. You won't be hurting Apple. And Apple won't feel like they've been abandoned. You're still using Webcore. And Safari is free so Apple isn't losing money or sleep over people not using it.
I don't see customizable toolbars as a "neat-o feature." I think they should be part of any respectable OS X-native application that uses toolbars. Yeah, there are some things that should stay to more full-featured browsers, and some that can go ahead and go into the simple ones. I personally see tabs as a minor feature that don't overload you with complexity. After all, tabs in Safari are completely off by default (or at least I think so) and you have to go in and make a conscious effort to turn them on if you want to use them. That way, if you're confused by tabs or you just don't like them, you won't have to use them. In fact, you won't even be reminded of their presence, because you won't have to use complicated commands like "cmd-shift-click" to open a link in a new window instead of a new tab - it's cmd-click to open a new window OR a new tab depending on your preference. I know tabs vs. no tabs has been argued before but I have a hard time believing that you anti-tabbers are such good samaritans that you don't want ANYONE using tabs because of how evil they are... but nevermind that, I'll try not to argue too much about tabs vs. no tabs because it's been covered extensively to no avail.
Do Omni a favor and get OmniWeb if you want super-features...and leave Safari alone as a cute little browser for people that don't want anything else.
I can't wait to see the next version of OW! I probably won't buy it unless it's really really awesome, but I'll at least try it out. It does take quite a browser to get people to pay for it, considering most are free.