I was researching this last week. My reason was I wanted to brew a double batch, but my 10 gallon brewpot is not big enough. It was suggested that keeping the wort warm would prevent it from souring, but some brewers were not having a problem either chilling it or doing nothing but sealing it and letting it sit until the next day.
So, just because I could, I went with the keep it warm method last night. I have a 3000W HLT that works great, but its not enough power to boil. (I use gas for that.) After the last sparge, I emptied the HLT and transferred the wort for the second batch into it and set it to 165 degrees. I boiled the first batch, pitched yeast around midnight and went to bed. Today I drained the HLT into my brewpot and boiled the second batch.
This really doesnt help you, because it will be a while before the beer ready, but there was no sour smell so Im optimistic. The extending time in the pasteurization range should keep anything from growing, I just dont know if it will effect the taste of the final product.