A little information for those not familiar with St. Louis:
The new stadium would basically be put in the last blighted part of the Riverfront; at least from well south of the Arch - where Busch Stadium is located - to the new Stan Musial Interstate 70 Bridge, just north of the stadium. The only old building that would be retained, to my knowledge, is the old powerhouse located on the Mississippi; similar to Camden Yards in Baltimore maintaining the old warehouses beyond Right Field.
Someone asked about windiness near the River. Trust me - the River is NOT a substantial enough body of water to create wind; at least, not in the manner of a body of water like Lake Michigan. The Mississippi River bottom is instead more renowned for high humidity - but only during the dog days of the summer; not during football season.
And the talk about cold? Sure - it's not San Diego; but I grew up in Michigan and Wisconsin, where you put your Halloween costume over your snowsuit! One of the things I love about St. Louis is that golf season is 9-10 months long; unlike even Chicago, some 270 miles north. I was curious, so I looked up the average temperatures in St. Louis for the relevant months; this is what I found:
September - average high 80 degrees; average low 61 degrees.
October - average high 69 degrees; average low 49 degrees.
November - average high 56 degrees; average low 38 degrees.
December - average high 43 degrees; average low 27 degrees.
January - average high 40 degrees; average low 24 degrees.
In most seasons, there would only be two regular season games in December; and based on history, half would be played in temperatures above 43 degrees; half below 43 degrees. Chilly? Of Course! But hardly frozen-tundra-like.
I recall one playoff game many years ago in Cincinnati in brutal cold. The climate of Cincinnati is similar to that of St. Louis. But I think climate variables add to the charm of a football game; and a below-freezing game in St. Louis would be very much the exception, not the rule.
Having come from the upper midwest, my sense is that - apart from a very short spring (it gets hot here quick!) - the weather in St. Louis typically follows the calendar, so that Autumn typically in fact lasts into December. And, while a "default" day in Chicago, Wisconsin or Michigan may be overcast - a "default" day in St. Louis is at least partly sunny.
Trust me, over the past 20 years, there've been many, many times when we hated to go from outdoor tailgating to football inside the Dome; retractable roof is nice, but not necessary here.