I don't think so. He is doing very well in MMA. He will not get a high profiled fight in Boxing unless he beats a few gatekeepers.
Not too much, MMA fans prefer watching MMA, thats why they are MMA fans. Leko and the other K1 guys who went to boxing didn't bring the K1 fans, Pulver didn't really bring many MMA fans to his boxing career, which gets overlooked, he was on ESPN afterall; those guys are not Silva in terms of drawing power, but outside of maybe one fight, the MMA fans will not follow Silva into other boxing matches. Silva gets paid more than all but the megastars of boxing, once he loses one fight, he would be making significantly less in boxing than he is in MMA. His earning potential is based around the fact that he is one of the greatest MMA fighters ever, to give that up is to give up millions of future dollars; long term picture he makes more doing what he does best, amazing MMA.
Is it time to rethink this now? Silva is bored in the UFC, wants a challenge and a big payday but who does he fight in a boxing ring? It would have to be a big name. Why not --Antonio Rogerio Nogueria (South American Heavyweight amatuer boxing champion) or Jeremy Williams or James Toney.....all at 205 lbs.