Optional stylus. Interesting and useful. Seems like the screen explicitly supports styli, as opposed to the iPad, where such support has been added after the fact, by third parties . Lenovo could get such a screen from N-Trig  which said in February that several Android tablets would be using their technology this summer.
Accessory: keyboard shell. Most intriguing aspect: it has a trackpad. This could greatly increase the usability when using the tablet in keyboard mode .
Availability: “it’s targeted for an August launch, but there are also a few mentions of July.” 
The Lenovo tablet being inserted into the optional keyboard shell [source: This is my next].