He isnt a Superman analog per se, but Stan Lee definitely had Superman in mind when he created Thor. I think Marvels first Superman analog was Hyperion. Nevertheless, Stan mentions him several times in his prologues for a few characters (Hulk, Thor and Spider-Man) in his book, Origins of Marvel Comics, by Stan Lee. With Hulk, he mentions creating a character with strength like Superman (but with an obvious twist). With Thor, Stan always wanted a "cape" at Marvel. He talked about how he never understood how Superman flew (and joked later at a university lecture that it was funny his response was to have a guy pulled around by a magic hammer). He also said he was hooked on superlatives at the time, " ...who could be stronger than the Hulk?", he mused. The only thing he could think of was that he would have to create "Super God". Then it hit him: he wouldnt do a strip featuring God, but he could do one featuring a god. Hence Thor was born.
Today, I suppose as far as Superman copy cats, marvel still has Hyperion, Blue Marvel, Sentry and a few others.