Please, Marc, why RockMelt?
Andreesen rose to fame as the founder of Netscape, the wildly successful browser that dominated the market until it was killed off by its own stagnation coupled with stiff (many would say "unfair") competition from Microsoft Internet Explorer, which comes bundled with Windows.
The thing is, competition is good if you're bringing something new to the table. Today we've got browser competition in spades. Most of these browsers have their selling points... MSIE, Safari and Konqueror are tightly integrated with their respective operating systems; FireFox offers unmatched extensibility; Chrome, simplicity; Opera, speed, tight coding, and strict adherence to published standards. It's not clear what, if anything, RockMelt will offer, and the tight-lipped silence doesn't cause me much excitement. I had enough of that when Segway teased us for months with "this is IT!" leaving us to ask, "that's it?" at the launch.
The fact is that Marc Andreesen just doesn't have a lot of credibility for me anymore when it comes to browsers... Netscape was popular, yes, but that was when it was the only game in town. When competition appeared in the first browser wars Netscape quickly became bloated, buggy, and slow. It went under not only because MSIE was free, but also because MSIE was a better product, and that was under Andreesen's watch. It took spinning off the Mozilla foundation and the creation of Firefox to come up with a better browser. So while it's nice that Andreesen wants to get back in the game, I hope the offering will be truly worth the effort, and not the product of some garage inventor who comes up with a better carbeuretor, ignoring the fact that the industry has long since moved past that.
But the secrecy thing...? That's just silly, so I won't waste a moment of time on speculation or anticipation.