Rashad will win, hands down. Unless he comes in cocky, which I don't think he will, considering his last fight.
I never guess how, but probably by knockout GNP.
Rashad was talking on Inside MMA about how straight forward Thiago's stance is and how he was going to work the Angles against Silva. I think he's right. Silva's a beast but Rashad is just that little bit quicker, agile and smarter, plus he's coming from a gym that tries to strategize to the letter. Also, Rashad's wrestling I believe will be able to put the fight where he wants it, and I think his GNP is one of his most underrated weapons.
Silva's strength, his confidence, will also be his downfall. While it works against fighters who are slower or have worse hands than him, rushing Rashad will not work. If he actually takes his time (which I don't he will) he could actually outstrike Rashad from a distance, as he has a more diverse stand up.