Wlad would need to consistently throw heavy punches to the body for that to happen though... Or would not have to? I wouldn't put anything past the apparentely vast army of pro-Ruiz refs in boxing.
I agree, these are the only two who I give a chance of beating Wlad in the near future. I curently favour Klitschko over both however. Other than those two I feel he beats everyone else in the division rather convingly, unless of course he gets randomly KTFO again.
Virchis has a chance, as has Valuev if he decides to make it rough and toss Wlad around the ring when it's hugging time. Sam has a chance too allthough I think Wlad improved more then Sam did. Wlad will make a mess of Povetkin, Chagaev will be on his bicycle for 12 rounds and make it a snoozefest. Lyakovich has an offchance too if he is allowed back in the gym. David Haye is out of his league imho. he will be chasing Wlad around like Sam did, but he hast got the chin for Wlads targetpractice.