This has annoyed me very much too. Using tab is not always desirable, for example when you're reading a large document. Tab could move away from where you were reading to the first link on the page.
I have found a work-around for the missing hotkey inspired by some of the answers from here: In Mac Chrome, how can I return focus from the address bar to the page?
Edit: Apparently this still gets upvotes. If this really bothers you please let the chrome devs know here: http://code.google.com/p/chromium/issues/detail?id=92885