The Senate is expected to roll out a plan next week to overhaul oversight of Fannie Mae and Freddie Mac, but it’s clear that there are still significant challenges to obtaining regulatory reform this year. The House jumped out in front of the curve this spring when the House Financial Services Committee approved H.R. 1461, which would create a new regulator for the government-sponsored enterprises, by a healthy 65 to 5 margin. Since that time,…