The arrow and orange square serve a purpose. If you click on it it'll take you to the first unread post in that topic.
I didn't even know that. (I wonder how many others didn't know its meaning). I always thought that the icon was trying to convey a complicated message that was somehow answered by the link next to it. Hieroglyphics written by programmers elude me. Just my 2 cents, but I think it would be easier for an average user to figure out its meaning by just using it. If only the icon looked interesting enough and inviting enough to click.
However, though the wonders of templates you can move that icon to whereever you like it (or remove it entirly).
Since it serves such a useful purpose, I'm going to keep it.
I think a subtle white arrow without the square would be an improvement. I'm sure there is something better. Would I be able to replace the default icon with another and have the same functionality?