The favicon does not serve any interactive purpose. It shows up when swiping left and right through the awesome bar with Talkback in Jelly Bean, but only introduces unnecessary noise. Since this is a non-interactive element that also does not serve any useful informational purpose, it should be removed from the swiping order. It already is not discoverable via Explore By Touch because it has no contentDescription.
The favicon is becoming useful! Tapping on it will open the site security popup, since it will be paired with the "lock" button. See bug 771380.
Thanks, Mark, for jumping in! I'll close this one WFM and have it depend on bug 771380.
Bug 771380 actually removed the favicon from the swiping order, at least for Jelly Bean, and is generally inaccessible due to a non-present contentDescription in prior JB environments, so changing resolution from WONTFIX to WFM. Also verified this in Nightly 17.0a1 2012-08-26.