Yeah, the Lenovo T420s has an array of mics up top around the webcam, and in theory they can be used to filter out noise from typing and be tuned to pick up the voice of the talker and not the speakers. But I went through all that calibration and it still sucks... it does filter out a lot of the keyboard noise but it also attacks the voice as well. Maybe someday Lenovo/Conexant will release better, more tunable drivers, but I haven't seen anything positive on any of the Lenovo support message boards yet.
In Lenovo's defense, I bought a z710 for my wife, and it appears to work great with Skype and stuff out of the box (though I've never sampled the audio quality on the far end of the call). It's a nice little desktop replacement box, at the time probably the cheapest laptop I could find with a 1920x1080 LCD and a half-decent NVidia GPU. Of course, it still has an Intel 4000 integrated GPU as well for "hybrid power savings"... you can't disable the iGPU, and the thing would BSOD with any 3D applications using the Nvidia GPU until I installed the right combination of driver updates relatively recently.