I'm sure an icon is very low on their priority list, and I don't blame them, nor do I mind. In the mean time, here's an alternative icon you can use. Just unzip it and place it in

/Applications/Sublime Text 2.app/Contents/Resources

(Tip: You have to right click or ctrl+click Sublime Text 2.app, and click "Show Application Contents" to get to the Contents folder)

Overwrite the old one and restart Sublime Text 2, and you should see your new icon. You'll have to do this for each build they release.

It looks like someone else made a different icon as well, made by Nate Beaty. You can grab it from this Nettuts tutorial.

Enjoy!