I don't think he'll be #1 any time soon. Letterman has stepped up his game when Conan began as host, and earned back the #1 spot in late night. Also, more and more people are watching Craig Ferguson now, so there's a strong block right there. Leno's damaged goods, and there will be fall out from this for a long time to come.
Also, the "don't blame Conan" statement was pure arrogance. No one has blamed Conan for anything, except NBC. Even that is misguided, as the network FIRST cancelled Leno's 10 pm slot, and shoehorned him back into the Tonight Show. Conan only did what any one would do, and stood up to the network. Conan would have been gone whether he had accepted the 12:05 slot or not, eventually. Leno (and his lawyers) positioned himself to land on his feet regardless of whatever happened with the 10 pm show.