Chromium is open-source. Whether or not it's platform-independent has nothing to do with it. Because it's open-source, continuity is no longer restricted to Google's whims. If they drop it tomorrow, popular demand will keep the project alive.
"stop calling Chrome open source, it isn't, chromium is" - other than the name, what's different? And please don't tell me "Chrome's more polished". That's only because Chromium has already entered another stage of development. Seriously, if Google wasn't committed to open-source, why would they even bother putting so many resources into Chromium? And one thing everybody who's asking "why didn't they release all three versions simultaneously?" are forgetting is that Chrome was a top-secret, need-to-know basis type of project in Google. They couldn't allocate the amount of resources they'd have liked to because of all the secrecy. This is no longer true. And now since the Windows launch is such a success, people will be eagerly waiting to see if they can pull the same thing off in Mac/Linux.
I think people are going to be very pleasantly surprised with Chrome's Linux launch - I wouldn't be surprised if it spurs Linux development and interest. Having seen their dedication to the Windows version, I KNOW they will release a stupendous version in the other platforms.
The best way to accelerate a Macintoy is at 9.8 meters per second per second.