Yeah, I don't see Marquardt beating Silva, either.
Some "MMA math"...
1. Marquardt is a submission fighter. Of his 25 pro wins, 12 were by submission hold, 7 were by decision, only 6 were by (T)KO or submission due to strikes.
2. Marquardt hasn't fought any high-quality strikers. The striking game is largely mitigated by Pancrase rules, and the only striker he's fought in the UFC was Crafton Wallace. I didn't see that fight, but I'm going to go out on a limb and declare that Silva is better than Wallace. Call me crazy.
3. Silva has two losses by submission hold on his pro record. The most recent was that crazy thing Chonan put on him in '04. People generally acknowledge that Chonan was winning that fight anyway, but the ending was nutso.
4. Silva has fought plenty of decent grapplers. Some people actually thought Travis Lutter was going to win that fight.
Anyway, I'd say Marquardt has one chance in three, and I'll be picking Silva to win by TKO without a second thought.