I'm curious as to why Teemo is considered "worthless". He is one of only three heroes (alongside Twisted Fate and Nidalee) with built-in map awareness. Admittedly his awareness is weaker than TF's (though almost certainly stronger than Nid's, as it gives you vision even if they don't trip it and it's invisible), but it still gives him a fairly unique element. And his blind is very good at eliminating the usefulness of an enemy carry in a teamfight. It's also the most reliable blind outisde of Exhaust (Heimer's is a slow-moving skillshot, Shaco's and Corki's aren't 100%) and has the longest duration of any blind. He also has one of the highest base attack speeds, making him decent as a carry, and his AP ratios are acceptable for him to be built AP as well.