here is my point of view.
i would pick machida in this one. here's why:
standing: i see silva getting the better of machida, BUT, machida is so elusive, nobody ever tagged him. he barely got hit in all of his fights. silva has the best striking, but in order to do some damage he needs to hit him. in order to hit machida, he needs to go after him. and we all know what happens to people who go after machida. and machida's striking very good, not as good as silva's but i would rank his striking in the top 5. easily.
wrestling/takedowns: i pick machida easy. he has great takedowns, great ground game. he is slightly bigger than silva and has the upper hand on this one. his jiu-jitsu is also good. not that silva has a poor ground game, but nobody realy tested him except lutter and hendo. lutter got wreckless and forgot basics and hendo didn't do a lot because he doesn't have great jiu jitsu.
all in all, i see machida comming out a winner out of this one, by decision.